R. Van Heerwaarden - Academia.edu (original) (raw)

Papers by R. Van Heerwaarden

Research paper thumbnail of 2.12.4 Multiple corrections of posttraumatic deformity and leg-length discrepancy due to growth disturbance

Osteotomies for Posttraumatic Deformities

Research paper thumbnail of Kniegelenkdistraktion bei der Behandlung schwerer Arthrose

Arthroskopie, 2020

Problem Es besteht ein Bedarf an gelenkerhaltenden Techniken wie der Kniegelenkdistraktion (KJD) ... more Problem Es besteht ein Bedarf an gelenkerhaltenden Techniken wie der Kniegelenkdistraktion (KJD) zur Behandlung der Gonarthrose bei relativ jungen Patienten. Wegen des erhöhten Risikos für Revisionsoperationen und der geringeren klinischen Wirksamkeit bei dieser Patientengruppe ist es wichtig, eine Knieendoprothese bei Patienten unter 65 Jahren zu vermeiden. Methoden Mit Hilfe eines externen Distraktionsdevice (KneeReviver, ArthroSave, Culemborg, Niederlande) werden die Kontaktbelastungen zwischen den beiden Knorpeloberflächen von Femur und Tibia über einen temporären 6‑wöchigen Behandlungszeitraum stark reduziert. Die in diesem Device verwendeten eingebauten Federn verursachen während der Belastung intermittierende Druckänderungen, was die Knorpelregeneration stimuliert. Ergebnisse Bei der 1‑Jahres-Nachbeobachtung wurde eine signifikante Abnahme der Schmerzen und eine Zunahme der Kniefunktion dokumentiert, vergleichbar mit der totalen Knieendoprothese (TKA) und der hohen Tibiaosteo...

Research paper thumbnail of 2.13.1 Osteotomies for malunions of the tibial head

Osteotomies for Posttraumatic Deformities

Research paper thumbnail of Osteotomies: The Surgical Details You Want to Know

A surgical plan for deformity correction can protect the patient undergoing osteotomies around th... more A surgical plan for deformity correction can protect the patient undergoing osteotomies around the knee, and the surgeon as well in case complications arise. Bulletpoints can be used as a list of things to do or not to forget when performing high tibial osteotomy (HTO) and distal femoral osteotomy (DFO). To enhance gap healing in open wedge HTO bone graft augmentation can be used with an added pain reduction effect as compared to no gap filling. Risks and complications of osteotomies are mentioned as well as the sense and nonsense of measures to decrease risks and prevent complications. Decision criteria to choose between HTO and unikondylar prosthesis (UKP) are made clear using constitutional deformity, ligament balance and grade of osteoarthritis.

Research paper thumbnail of Arthrodesis of a dislocated Charcot foot

Research paper thumbnail of 2.11.1 Osteotomy of the distal femur

Research paper thumbnail of 2.12.4 Multiple corrections of posttraumatic deformity and leg-length discrepancy due to growth disturbance

Research paper thumbnail of Effects of pretension in reconstructions of the anterior cruciate ligament: clinical, biomechanical and computer model analyses

Research paper thumbnail of Medial closing wedge high tibial osteotomy for valgus tibial deformities: good clinical results and survival with a mean 4.5 years of follow-up in 113 patients

Knee Surgery, Sports Traumatology, Arthroscopy

PurposeA varus-producing medial closing wedge high tibial osteotomy (MCWHTO) is an uncommon proce... more PurposeA varus-producing medial closing wedge high tibial osteotomy (MCWHTO) is an uncommon procedure. The aim of this retrospective study was to assess the survivorship and prevalence of post-operative subjective knee laxity and satisfaction in a large cohort of patients with a MCWHTO performed without a MCL-reefing procedure.MethodsAll patients (n = 176) who underwent a MCWHTO in our clinic between 2008 and 2016 were approached to participate. After review of patient charts, questionnaires were sent to willingly patients. Primary outcome was the survivorship of the MCWHTO; secondary outcome was patient-reported instability and satisfaction.ResultsOne-hundred and thirteen patients participated in the study. The 5-year survival rate of the MCWHTO was almost 80%. A total of 77% of the patients was satisfied with the treatment. With regard to post-operative subjective knee laxity, 26% of the patients experienced instability of the knee post-operation. Instability was significantly correlated with the KOOS domains, the Lysholm score, the IKDC knee function score and the Physical and Mental Health Domains of the SF-36.ConclusionMedial closing wedge high tibial osteotomy provides good results regarding survivorship and patient satisfaction for patients with a valgus deformity which is located in the proximal tibia. Clinically relevant is that in the surgical technique without MCL-reefplasty instability is significantly correlated with worse patient-reported outcome measures. The addition of a MCL reefing procedure will improve outcome in selected patients.Level of evidenceIII.

Research paper thumbnail of Medial collateral ligament laxity in valgus knee deformity before and after medial closing wedge high tibial osteotomy measured with instrumented laxity measurements and patient reported outcome

Journal of Experimental Orthopaedics

Introduction: Medial closing wedge high tibial osteotomy (CWHTO) for valgus deformity correction ... more Introduction: Medial closing wedge high tibial osteotomy (CWHTO) for valgus deformity correction was first described by Coventry whom performed an additional reefing of the medial collateral ligament (MCL) to prevent instability postoperative. In our clinic the additional reefing procedure has never been performed and instability has not been reported routinely by patients. Using instrumented laxity testing, pre-and postoperative valgus and varus knee laxity can be measured objectively. We hypothesize that absence of changes in laxity testing and subjective knee stability scores support that no additional reefing procedure is necessary. Materials and methods: In a prospective cohort study 11 consecutive patients indicated for medial CWHTO were subjected to pre-and postoperative stress X-rays in 30°and 70°of flexion and opening of the joint line was measured in degrees on the radiographs. Patient reported outcome scores were documented with the KOOS, Lysholm, SF36, Oxford Knee Score and a VAS instability scoring tool. Results: All patients (7 females) completed the study, mean age was 46 years. Mean preoperative Hip Knee Ankle angle 6.4°valgus was corrected to mean postoperative alignment 0.1°valgus. A significant difference was measured between mean pre-and postoperative 30°valgus laxity (2.8°vs 5.3°, P = 0.005), 30°varus laxity (6.7°vs 3.2°, P = 0.005) and 70°valgus laxity (2.0°vs 4.8°, P = 0.008). Postoperative patient-reported knee instability as measured with the Lysholm questionnaire was significantly improved compared to preoperative instability (P = 0.006). VAS instability improved, but didn't reach significance (8.0 preoperative and 5.5 postoperative (P = 0.127). Other outcome measures showed improvement as well. No correlations between radiological findings and outcome scores were found. Conclusion: A significant increase in postoperative valgus laxity in 30°and 70°of flexion deems reconsidering addition of MCL reefingplasty to the medial CWHTO although patient reported outcome on subjective stability scores fails to report increase of instability in this study population. Instrumented laxity measurements of medial CWHTO patients treated with additional medial reefingplasty should be performed to prove the value of this procedure.

Research paper thumbnail of Six weeks of continuous joint distraction appears sufficient for clinical benefit and cartilaginous tissue repair in the treatment of knee osteoarthritis

The Knee

BACKGROUND Knee joint distraction (KJD) is a surgical joint-preserving treatment in which the kne... more BACKGROUND Knee joint distraction (KJD) is a surgical joint-preserving treatment in which the knee joint is temporarily distracted by an external frame. It is associated with joint tissue repair and clinical improvement. Initially, patients were submitted to an eight-week distraction period, and currently patients are submitted to a six-week distraction period. This study evaluates whether a shorter distraction period influences the outcome. METHODS Both groups consisted of 20 patients. Clinical outcome was assessed by WOMAC questionnaires and VAS-pain. Cartilaginous tissue repair was assessed by radiographic joint space width (JSW) and MRI-observed cartilage thickness. RESULTS Baseline data between both groups were comparable. Both groups showed an increase in total WOMAC score; 24±4 in the six-week group and 32±5 in the eight-week group (both p<0.001). Mean JSW increased 0.9±0.3mm in the six-week group and 1.1±0.3mm in the eight-week group (p=0.729 between groups). The increase in mean cartilage thickness on MRI was 0.6±0.2mm in the eight-week group and 0.4±0.1mm in the six-week group (p=0.277). CONCLUSIONS A shorter distraction period does not influence short-term clinical and structural outcomes statistically significantly, although effect sizes tend to be smaller in six week KJD as compared to eight week KJD.

Research paper thumbnail of Distale Femurosteotomie in schließender biplanarer Technik mit Stabilisierung durch spezifischen Plattenfixateur

Operative Orthopädie und Traumatologie

ZusammenfassungOperationszielKorrektur von Frontalebenendeformitäten am distalen Femur in biplana... more ZusammenfassungOperationszielKorrektur von Frontalebenendeformitäten am distalen Femur in biplanarer Closed-wedge-Technik.IndikationenFemorale metaphysäre Deformitäten in der Frontalebene.KontraindikationenFortgeschrittene Knorpelschäden/totaler Meniskusverlust im kontralateralen Kompartiment, akute/chronische Entzündungen, ungenügende Weichteilverhältnisse, erhebliche Bewegungseinschränkung im Kniegelenk.OperationstechnikHautschnitt über Femurmetaphyse, begrenzte Freilegung des Knochens. Festlegung von primärer Osteotomie und aufsteigender biplanarer Osteotomie. Posterior zwei inkomplette Osteotomien des distalen Femurs zur Keilentnahme. Aufsteigender Sägeschnitt in der Frontalebene. Entnahme des Knochenkeils und Schließen der Osteotomie. Radiologische Beinachsenkontrolle. Einbringen der TomoFix-MDF-Platte submuskulär. Fixation und Wundverschluss.WeiterbehandlungKompressionsverband, Redonentfernung und Mobilisation am 1. Tag. 15‑kg-Teilbelastung für 4 Wochen; Röntgenkontrolle am 3. postoperativen Tag sowie nach 4 Wochen, danach Belastungssteigerung; Thromboseprophylaxe.ErgebnisseVon Januar 2005 bis Oktober 2008 60 varisierende Femurosteotomien in Closed-wedge-Technik mit TomoFix-MDF, davon 30 in biplanarer Technik. Mittleres Alter 39,7 Jahre; mittleres Korrekturausmaß 7,6 mm; mittleres Follow-up 21 Monate; 7 Revisionsoperationen: 3 Pseudarthrosen, eine Hämatomentlastung, eine oberflächliche, eine tiefe Infektion, eine Fraktur nach Sturz. Tegner-Score prä‑/postoperativ 2,8 (1–4)/5,6 (2–9); VAS prä‑/postoperativ 6,8 (9–2)/3,1 (0–8). Zweite Auswertung von 107 distalen Femurosteotomien von 2014–2015: 4 verzögerte Heilungen, ein Plattenbruch. Ausheilung aller anderen Osteotomien in 4–6 Wochen. Mit muskelschonender Operationstechnik keine eingeschränkte Beugung.AbstractObjectiveCorrection of distal femur deformity by closed-wedge biplanar osteotomy.IndicationsMetaphyseal frontal plane deformities of the femur.ContraindicationsOsteoarthritis of the contralateral compartment, total loss of the contralateral meniscus, acute/chronic infection, limited range-of-motion, poor soft-tissue conditions at site of surgery.Surgical techniqueSkin incision at metaphyseal area of femur. Local exposure of bone. Marking of planned osteotomies. Incomplete posterior osteotomies, complete anterior osteotomy. Wedge removal and closure. Radiological control of alignment. Fixation with specific plate fixator for the medial femur (TomoFix MDF). Submuscular plate fixation. Wound closure.Postoperative managementElastic bandage, suction drain removal and walking with crutches on day 1. Partial weight bearing (15 kg) for the first 4 weeks; X‑ray control on day 3 and 4 weeks after surgery, walking without crutches depending on healing of osteotomy. Thrombosis prophylaxis.ResultsFrom January 2005 to October 2008, 60 patients were treated. Average wedge size 7.6 mm; age 39.7 years; mean follow-up 21 months; 7 revision surgeries: 3 delayed/nonunion of the osteotomy, one superficial infection, one deep infection, one hematoma, and one fracture proximal of the internal plate fixator. Tegner activity score pre‑/postoperative 2.8 (1–4)/5.6 (2–9); VAS score pre‑/postoperative 6.8 (2–9)/3.1 (0–8). From 2014–2015, 107 femur osteotomies performed: 4 delayed healing, one plate breakage. Healing of all other osteotomies in 4–6 weeks. No loss of range-of-motion with the muscle-sparing surgical technique.

Research paper thumbnail of Knee joint distraction compared with total knee prosthesis: A randomized controlled trial (preliminary results)

Osteoarthritis and Cartilage

Research paper thumbnail of Periosteal vascularization of the distal femur in relation to distal femoral osteotomies: a cadaveric study

Journal of Experimental Orthopaedics

Background: The purpose of this study was to investigate periosteal vessels location as intra-ope... more Background: The purpose of this study was to investigate periosteal vessels location as intra-operative landmarks in distal femoral osteotomies and focused on the branching pattern of the vascular supply of the medial and lateral femoral condyle, its constancy, and the relationship to the height of distal femoral osteotomies. Anastomoses of relevant vessels were studied to analyze the risk of vascular insufficiency after transection of landmark vessels. Methods: A human cadaver dissection study on the vascular supply of the medial and lateral side of the distal femur was conducted. Surgical dissection was performed in eight knees in total. Distances between the vascular supply and bony landmarks were calculated. Relation of the vascular structures to the transverse bone cuts of distal femoral osteotomies was described, as well as anastomoses of relevant vessels. Results: On the medial side of the distal femur the periosteum was primarily supplied by the descending genicular artery (DGA) in 87.5 % of the specimens. In the absence of the DGA, the superior medial genicular artery was the supplier. Vascularization took place through two constant branches, the upper transverse artery (UTA) and the central longitudinal artery. The UTA originated at a mean distance of 6.9 cm (range 5.9-7.9 cm) above the knee joint line. On the lateral side of the distal femur the superior lateral genicular artery was the main vessel. In all dissected knees it gave off the lateral transverse artery (LTA). The LTA originated at a mean distance of 6.9 cm (range 5.8-7.6 cm) above the knee joint line. Anastomoses between the UTA, LTA and the longitudinal arch of the femoral shaft were found that could prevent vascular insufficiencies after transection of the UTA and LTA. Conclusions: The vascular supply of the medial and lateral aspects of the femoral condyle is highly constant. Both the UTA, on the medial side, and the LTA, on the lateral side, can serve as a landmark for orthopedic surgeons in determining the height of the osteotomy cuts in distal femoral osteotomies. Transection of these landmark vessels during the osteotomy will not result in vascular insufficiency because of a collateral supply.

Research paper thumbnail of Gait analysis before and after corrective osteotomy in patients with knee osteoarthritis and a valgus deformity

Knee surgery, sports traumatology, arthroscopy : official journal of the ESSKA, Jan 18, 2016

In this prospective study, the changes in kinetics and kinematics of gait and clinical outcomes a... more In this prospective study, the changes in kinetics and kinematics of gait and clinical outcomes after a varus osteotomy (tibial, femoral or double osteotomy) in patients with osteoarthritis (OA) of the knee and a valgus leg alignment were analysed and compared to healthy subjects. Twelve patients and ten healthy controls were included. Both kinetics and kinematics of gait and clinical and radiographic outcomes were evaluated. The knee adduction moment increased significantly postoperatively (p < 0.05) and almost similar to the control group. Patients showed less knee and hip flexion/extension motion and moment during gait pre- and postoperatively compared to the controls. A significant improvement was found in WOMAC [80.8 (SD 16.1), p = 0.000], KOS [74.9 (SD 14.7), p = 0.018], OKS [21.2 (SD 7.5), p = 0.000] and VAS-pain [32.9 (SD 20.9), p = 0.003] in all patients irrespective of the osteotomy technique used. The radiographic measurements showed a mean hip knee ankle (HKA) angle c...

Research paper thumbnail of Effect of pretension in reconstructions of the anterior cruciate ligament with a Dacron prosthesis

Knee Surgery, Sports Traumatology, Arthroscopy, 1996

To study the effect of the pretension level in reconstructions of the anterior cruciate ligament ... more To study the effect of the pretension level in reconstructions of the anterior cruciate ligament (ACL) we examined 26 patients with isolated ACL insufficiency and intact Dacron ligament prosthesis at 4-year follow-up. The patients were divided into two groups of 13 each, based on pretension level applied at the reconstruction: in group I the ligament was pretensioned to 60 N and in group II to 40 N. The patients were evaluated by the Tegner and Lysholm scores, KT-1000 arthrometer measurements, and isokinetic muscle performance testing and were assessed by the Knee Ligament Standard Evaluation Form of the International Knee Documentation Committee. At followup there were no differences between the two groups in any of the evaluated parameters except for squatting ability. The two groups differed significantly (P < 0.01) with regard to the squatting score: 11 patients in group I had decreased squatting ability, and 6 of these were not able to squat beyond 90 ~ of flexion. In contrast, only 4 patients in group II had slightly impaired squatting ability. It is likely that this difference between the two groups is related to the magnitude of the pretension applied to the ligament prosthesis, and that the pretension exerts its influence through a change in the knee kinematics introduced at the time of the reconstruction.

Research paper thumbnail of Valgus bracing in patients with medial compartment osteoarthritis of the knee

Gait & Posture, 2007

A new valgus brace was evaluated in 15 patients with medial osteoarthritis of the knee and a varu... more A new valgus brace was evaluated in 15 patients with medial osteoarthritis of the knee and a varus leg axis. Significant improvement of pain and function were found after 6 weeks of brace treatment. Gait analysis showed that the brace had a tendency of lowering the peak varus moment about the knee. This effect was more profound in the presence of higher initial varus deformity angle of the knee. Furthermore, bracing led to a small decrease of knee extension at the end of the swing phase and an increase of walking velocity. The mechanisms identified by gait analysis in this study may be of clinical importance for future developments in brace treatment.

Research paper thumbnail of Valgus bracing in patients with medial compartment osteoarthritis of the knee: a gait analysis study of a new brace

Gait & posture, 2007

A new valgus brace was evaluated in 15 patients with medial osteoarthritis of the knee and a varu... more A new valgus brace was evaluated in 15 patients with medial osteoarthritis of the knee and a varus leg axis. Significant improvement of pain and function were found after 6 weeks of brace treatment. Gait analysis showed that the brace had a tendency of lowering the peak ...

Research paper thumbnail of Axial and torsional stability of supracondylar femur osteotomies: biomechanical comparison of the stability of five different plate and osteotomy configurations

Knee Surgery, Sports Traumatology, Arthroscopy, 2011

Purpose Little is known regarding the biomechanical stability and stiffness of implants and techn... more Purpose Little is known regarding the biomechanical stability and stiffness of implants and techniques used in supracondylar femur osteotomies (SCO). Therefore, fixation stability and stiffness of implants to bone was investigated under simulated physiological loading conditions using a composite femur model and a 3D motion-analysis system. Methods Five osteotomy configurations were investigated: (1) oblique medial closing-wedge fixated with an angle-stable implant; (2) oblique and (3) perpendicular medial closing-wedge, both fixated with an angled blade plate; and lateral opening-wedge fixated with (4) a spacer plate and (5) an angle-stable lateral implant. The motion measured at the osteotomy was used to calculate the stiffness and stability of the constructs. Results The least amount of motion and highest stiffness was measured in the medial oblique closing-wedge osteotomy fixated with the angled blade plate. The lateral opening-wedge techniques were less stable and had a lower stiffness compared with the medial; the oblique saw cuts were more stable and had a higher stiffness than the perpendicular. Conclusion This experimental study presents baseline data on the differences in the primary stability of bone-implant constructs used in SCO. The data in this study can be used as reference for future testing of SCO techniques. Furthermore, it is recommended that based on the differences found, the early postoperative rehabilitation protocol is tailored to the stability and stiffness of the fixation method used.

Research paper thumbnail of Distal femoral valgus osteotomy: bone healing time in single plane and biplanar technique

Strategies in Trauma and Limb Reconstruction

Varus deformity can be localized in the tibia, in the femur or in both. If varus deformity is loc... more Varus deformity can be localized in the tibia, in the femur or in both. If varus deformity is localized within the femur, it is mandatory to correct it in the femur. This report presents the technique and results of a consecutive case series of lateral uniplanar and biplanar closed-wedge valgus osteotomy of the distal femur for the treatment of varus deformity of the knee. Retrospectively, fifteen patients (sixteen knees) were identified. Indications for surgery varied from unloading an osteoarthritic medial compartment to reduction to symmetrical varus leg alignment. Pre-and post-operative X-rays, including a full leg radiograph, were assessed as well as bone healing time at follow-up intervals. Clinical outcome was assessed using different questionnaires. There were nine male and six female patients with a median age at surgery of 45 (±14) years. The mLDFA changed from 95.9°(±2.7°) preoperatively to 89.3°(±2.9°) post-operatively. Preoperative planning and the use of angle stable implants resulted in accurate corrections according to preoperative aims in all but one patient. At follow-up (mean, 40 months), the mean VAS score was 2.5 (±2.4) and the WOMAC score averaged 80 (±20). The mean bone healing time of biplanar osteotomies (4 ± 3 months) was shorter than in the uniplanar osteotomies (6 ± 3 months). Distal lateral closedwedge valgus osteotomy of the femur for the treatment of femoral varus deformities resulted in clinical improvement and accurate corrections in patients with different aims for correction. A biplanar osteotomy technique shortens bone healing time.

Research paper thumbnail of 2.12.4 Multiple corrections of posttraumatic deformity and leg-length discrepancy due to growth disturbance

Osteotomies for Posttraumatic Deformities

Research paper thumbnail of Kniegelenkdistraktion bei der Behandlung schwerer Arthrose

Arthroskopie, 2020

Problem Es besteht ein Bedarf an gelenkerhaltenden Techniken wie der Kniegelenkdistraktion (KJD) ... more Problem Es besteht ein Bedarf an gelenkerhaltenden Techniken wie der Kniegelenkdistraktion (KJD) zur Behandlung der Gonarthrose bei relativ jungen Patienten. Wegen des erhöhten Risikos für Revisionsoperationen und der geringeren klinischen Wirksamkeit bei dieser Patientengruppe ist es wichtig, eine Knieendoprothese bei Patienten unter 65 Jahren zu vermeiden. Methoden Mit Hilfe eines externen Distraktionsdevice (KneeReviver, ArthroSave, Culemborg, Niederlande) werden die Kontaktbelastungen zwischen den beiden Knorpeloberflächen von Femur und Tibia über einen temporären 6‑wöchigen Behandlungszeitraum stark reduziert. Die in diesem Device verwendeten eingebauten Federn verursachen während der Belastung intermittierende Druckänderungen, was die Knorpelregeneration stimuliert. Ergebnisse Bei der 1‑Jahres-Nachbeobachtung wurde eine signifikante Abnahme der Schmerzen und eine Zunahme der Kniefunktion dokumentiert, vergleichbar mit der totalen Knieendoprothese (TKA) und der hohen Tibiaosteo...

Research paper thumbnail of 2.13.1 Osteotomies for malunions of the tibial head

Osteotomies for Posttraumatic Deformities

Research paper thumbnail of Osteotomies: The Surgical Details You Want to Know

A surgical plan for deformity correction can protect the patient undergoing osteotomies around th... more A surgical plan for deformity correction can protect the patient undergoing osteotomies around the knee, and the surgeon as well in case complications arise. Bulletpoints can be used as a list of things to do or not to forget when performing high tibial osteotomy (HTO) and distal femoral osteotomy (DFO). To enhance gap healing in open wedge HTO bone graft augmentation can be used with an added pain reduction effect as compared to no gap filling. Risks and complications of osteotomies are mentioned as well as the sense and nonsense of measures to decrease risks and prevent complications. Decision criteria to choose between HTO and unikondylar prosthesis (UKP) are made clear using constitutional deformity, ligament balance and grade of osteoarthritis.

Research paper thumbnail of Arthrodesis of a dislocated Charcot foot

Research paper thumbnail of 2.11.1 Osteotomy of the distal femur

Research paper thumbnail of 2.12.4 Multiple corrections of posttraumatic deformity and leg-length discrepancy due to growth disturbance

Research paper thumbnail of Effects of pretension in reconstructions of the anterior cruciate ligament: clinical, biomechanical and computer model analyses

Research paper thumbnail of Medial closing wedge high tibial osteotomy for valgus tibial deformities: good clinical results and survival with a mean 4.5 years of follow-up in 113 patients

Knee Surgery, Sports Traumatology, Arthroscopy

PurposeA varus-producing medial closing wedge high tibial osteotomy (MCWHTO) is an uncommon proce... more PurposeA varus-producing medial closing wedge high tibial osteotomy (MCWHTO) is an uncommon procedure. The aim of this retrospective study was to assess the survivorship and prevalence of post-operative subjective knee laxity and satisfaction in a large cohort of patients with a MCWHTO performed without a MCL-reefing procedure.MethodsAll patients (n = 176) who underwent a MCWHTO in our clinic between 2008 and 2016 were approached to participate. After review of patient charts, questionnaires were sent to willingly patients. Primary outcome was the survivorship of the MCWHTO; secondary outcome was patient-reported instability and satisfaction.ResultsOne-hundred and thirteen patients participated in the study. The 5-year survival rate of the MCWHTO was almost 80%. A total of 77% of the patients was satisfied with the treatment. With regard to post-operative subjective knee laxity, 26% of the patients experienced instability of the knee post-operation. Instability was significantly correlated with the KOOS domains, the Lysholm score, the IKDC knee function score and the Physical and Mental Health Domains of the SF-36.ConclusionMedial closing wedge high tibial osteotomy provides good results regarding survivorship and patient satisfaction for patients with a valgus deformity which is located in the proximal tibia. Clinically relevant is that in the surgical technique without MCL-reefplasty instability is significantly correlated with worse patient-reported outcome measures. The addition of a MCL reefing procedure will improve outcome in selected patients.Level of evidenceIII.

Research paper thumbnail of Medial collateral ligament laxity in valgus knee deformity before and after medial closing wedge high tibial osteotomy measured with instrumented laxity measurements and patient reported outcome

Journal of Experimental Orthopaedics

Introduction: Medial closing wedge high tibial osteotomy (CWHTO) for valgus deformity correction ... more Introduction: Medial closing wedge high tibial osteotomy (CWHTO) for valgus deformity correction was first described by Coventry whom performed an additional reefing of the medial collateral ligament (MCL) to prevent instability postoperative. In our clinic the additional reefing procedure has never been performed and instability has not been reported routinely by patients. Using instrumented laxity testing, pre-and postoperative valgus and varus knee laxity can be measured objectively. We hypothesize that absence of changes in laxity testing and subjective knee stability scores support that no additional reefing procedure is necessary. Materials and methods: In a prospective cohort study 11 consecutive patients indicated for medial CWHTO were subjected to pre-and postoperative stress X-rays in 30°and 70°of flexion and opening of the joint line was measured in degrees on the radiographs. Patient reported outcome scores were documented with the KOOS, Lysholm, SF36, Oxford Knee Score and a VAS instability scoring tool. Results: All patients (7 females) completed the study, mean age was 46 years. Mean preoperative Hip Knee Ankle angle 6.4°valgus was corrected to mean postoperative alignment 0.1°valgus. A significant difference was measured between mean pre-and postoperative 30°valgus laxity (2.8°vs 5.3°, P = 0.005), 30°varus laxity (6.7°vs 3.2°, P = 0.005) and 70°valgus laxity (2.0°vs 4.8°, P = 0.008). Postoperative patient-reported knee instability as measured with the Lysholm questionnaire was significantly improved compared to preoperative instability (P = 0.006). VAS instability improved, but didn't reach significance (8.0 preoperative and 5.5 postoperative (P = 0.127). Other outcome measures showed improvement as well. No correlations between radiological findings and outcome scores were found. Conclusion: A significant increase in postoperative valgus laxity in 30°and 70°of flexion deems reconsidering addition of MCL reefingplasty to the medial CWHTO although patient reported outcome on subjective stability scores fails to report increase of instability in this study population. Instrumented laxity measurements of medial CWHTO patients treated with additional medial reefingplasty should be performed to prove the value of this procedure.

Research paper thumbnail of Six weeks of continuous joint distraction appears sufficient for clinical benefit and cartilaginous tissue repair in the treatment of knee osteoarthritis

The Knee

BACKGROUND Knee joint distraction (KJD) is a surgical joint-preserving treatment in which the kne... more BACKGROUND Knee joint distraction (KJD) is a surgical joint-preserving treatment in which the knee joint is temporarily distracted by an external frame. It is associated with joint tissue repair and clinical improvement. Initially, patients were submitted to an eight-week distraction period, and currently patients are submitted to a six-week distraction period. This study evaluates whether a shorter distraction period influences the outcome. METHODS Both groups consisted of 20 patients. Clinical outcome was assessed by WOMAC questionnaires and VAS-pain. Cartilaginous tissue repair was assessed by radiographic joint space width (JSW) and MRI-observed cartilage thickness. RESULTS Baseline data between both groups were comparable. Both groups showed an increase in total WOMAC score; 24±4 in the six-week group and 32±5 in the eight-week group (both p<0.001). Mean JSW increased 0.9±0.3mm in the six-week group and 1.1±0.3mm in the eight-week group (p=0.729 between groups). The increase in mean cartilage thickness on MRI was 0.6±0.2mm in the eight-week group and 0.4±0.1mm in the six-week group (p=0.277). CONCLUSIONS A shorter distraction period does not influence short-term clinical and structural outcomes statistically significantly, although effect sizes tend to be smaller in six week KJD as compared to eight week KJD.

Research paper thumbnail of Distale Femurosteotomie in schließender biplanarer Technik mit Stabilisierung durch spezifischen Plattenfixateur

Operative Orthopädie und Traumatologie

ZusammenfassungOperationszielKorrektur von Frontalebenendeformitäten am distalen Femur in biplana... more ZusammenfassungOperationszielKorrektur von Frontalebenendeformitäten am distalen Femur in biplanarer Closed-wedge-Technik.IndikationenFemorale metaphysäre Deformitäten in der Frontalebene.KontraindikationenFortgeschrittene Knorpelschäden/totaler Meniskusverlust im kontralateralen Kompartiment, akute/chronische Entzündungen, ungenügende Weichteilverhältnisse, erhebliche Bewegungseinschränkung im Kniegelenk.OperationstechnikHautschnitt über Femurmetaphyse, begrenzte Freilegung des Knochens. Festlegung von primärer Osteotomie und aufsteigender biplanarer Osteotomie. Posterior zwei inkomplette Osteotomien des distalen Femurs zur Keilentnahme. Aufsteigender Sägeschnitt in der Frontalebene. Entnahme des Knochenkeils und Schließen der Osteotomie. Radiologische Beinachsenkontrolle. Einbringen der TomoFix-MDF-Platte submuskulär. Fixation und Wundverschluss.WeiterbehandlungKompressionsverband, Redonentfernung und Mobilisation am 1. Tag. 15‑kg-Teilbelastung für 4 Wochen; Röntgenkontrolle am 3. postoperativen Tag sowie nach 4 Wochen, danach Belastungssteigerung; Thromboseprophylaxe.ErgebnisseVon Januar 2005 bis Oktober 2008 60 varisierende Femurosteotomien in Closed-wedge-Technik mit TomoFix-MDF, davon 30 in biplanarer Technik. Mittleres Alter 39,7 Jahre; mittleres Korrekturausmaß 7,6 mm; mittleres Follow-up 21 Monate; 7 Revisionsoperationen: 3 Pseudarthrosen, eine Hämatomentlastung, eine oberflächliche, eine tiefe Infektion, eine Fraktur nach Sturz. Tegner-Score prä‑/postoperativ 2,8 (1–4)/5,6 (2–9); VAS prä‑/postoperativ 6,8 (9–2)/3,1 (0–8). Zweite Auswertung von 107 distalen Femurosteotomien von 2014–2015: 4 verzögerte Heilungen, ein Plattenbruch. Ausheilung aller anderen Osteotomien in 4–6 Wochen. Mit muskelschonender Operationstechnik keine eingeschränkte Beugung.AbstractObjectiveCorrection of distal femur deformity by closed-wedge biplanar osteotomy.IndicationsMetaphyseal frontal plane deformities of the femur.ContraindicationsOsteoarthritis of the contralateral compartment, total loss of the contralateral meniscus, acute/chronic infection, limited range-of-motion, poor soft-tissue conditions at site of surgery.Surgical techniqueSkin incision at metaphyseal area of femur. Local exposure of bone. Marking of planned osteotomies. Incomplete posterior osteotomies, complete anterior osteotomy. Wedge removal and closure. Radiological control of alignment. Fixation with specific plate fixator for the medial femur (TomoFix MDF). Submuscular plate fixation. Wound closure.Postoperative managementElastic bandage, suction drain removal and walking with crutches on day 1. Partial weight bearing (15 kg) for the first 4 weeks; X‑ray control on day 3 and 4 weeks after surgery, walking without crutches depending on healing of osteotomy. Thrombosis prophylaxis.ResultsFrom January 2005 to October 2008, 60 patients were treated. Average wedge size 7.6 mm; age 39.7 years; mean follow-up 21 months; 7 revision surgeries: 3 delayed/nonunion of the osteotomy, one superficial infection, one deep infection, one hematoma, and one fracture proximal of the internal plate fixator. Tegner activity score pre‑/postoperative 2.8 (1–4)/5.6 (2–9); VAS score pre‑/postoperative 6.8 (2–9)/3.1 (0–8). From 2014–2015, 107 femur osteotomies performed: 4 delayed healing, one plate breakage. Healing of all other osteotomies in 4–6 weeks. No loss of range-of-motion with the muscle-sparing surgical technique.

Research paper thumbnail of Knee joint distraction compared with total knee prosthesis: A randomized controlled trial (preliminary results)

Osteoarthritis and Cartilage

Research paper thumbnail of Periosteal vascularization of the distal femur in relation to distal femoral osteotomies: a cadaveric study

Journal of Experimental Orthopaedics

Background: The purpose of this study was to investigate periosteal vessels location as intra-ope... more Background: The purpose of this study was to investigate periosteal vessels location as intra-operative landmarks in distal femoral osteotomies and focused on the branching pattern of the vascular supply of the medial and lateral femoral condyle, its constancy, and the relationship to the height of distal femoral osteotomies. Anastomoses of relevant vessels were studied to analyze the risk of vascular insufficiency after transection of landmark vessels. Methods: A human cadaver dissection study on the vascular supply of the medial and lateral side of the distal femur was conducted. Surgical dissection was performed in eight knees in total. Distances between the vascular supply and bony landmarks were calculated. Relation of the vascular structures to the transverse bone cuts of distal femoral osteotomies was described, as well as anastomoses of relevant vessels. Results: On the medial side of the distal femur the periosteum was primarily supplied by the descending genicular artery (DGA) in 87.5 % of the specimens. In the absence of the DGA, the superior medial genicular artery was the supplier. Vascularization took place through two constant branches, the upper transverse artery (UTA) and the central longitudinal artery. The UTA originated at a mean distance of 6.9 cm (range 5.9-7.9 cm) above the knee joint line. On the lateral side of the distal femur the superior lateral genicular artery was the main vessel. In all dissected knees it gave off the lateral transverse artery (LTA). The LTA originated at a mean distance of 6.9 cm (range 5.8-7.6 cm) above the knee joint line. Anastomoses between the UTA, LTA and the longitudinal arch of the femoral shaft were found that could prevent vascular insufficiencies after transection of the UTA and LTA. Conclusions: The vascular supply of the medial and lateral aspects of the femoral condyle is highly constant. Both the UTA, on the medial side, and the LTA, on the lateral side, can serve as a landmark for orthopedic surgeons in determining the height of the osteotomy cuts in distal femoral osteotomies. Transection of these landmark vessels during the osteotomy will not result in vascular insufficiency because of a collateral supply.

Research paper thumbnail of Gait analysis before and after corrective osteotomy in patients with knee osteoarthritis and a valgus deformity

Knee surgery, sports traumatology, arthroscopy : official journal of the ESSKA, Jan 18, 2016

In this prospective study, the changes in kinetics and kinematics of gait and clinical outcomes a... more In this prospective study, the changes in kinetics and kinematics of gait and clinical outcomes after a varus osteotomy (tibial, femoral or double osteotomy) in patients with osteoarthritis (OA) of the knee and a valgus leg alignment were analysed and compared to healthy subjects. Twelve patients and ten healthy controls were included. Both kinetics and kinematics of gait and clinical and radiographic outcomes were evaluated. The knee adduction moment increased significantly postoperatively (p < 0.05) and almost similar to the control group. Patients showed less knee and hip flexion/extension motion and moment during gait pre- and postoperatively compared to the controls. A significant improvement was found in WOMAC [80.8 (SD 16.1), p = 0.000], KOS [74.9 (SD 14.7), p = 0.018], OKS [21.2 (SD 7.5), p = 0.000] and VAS-pain [32.9 (SD 20.9), p = 0.003] in all patients irrespective of the osteotomy technique used. The radiographic measurements showed a mean hip knee ankle (HKA) angle c...

Research paper thumbnail of Effect of pretension in reconstructions of the anterior cruciate ligament with a Dacron prosthesis

Knee Surgery, Sports Traumatology, Arthroscopy, 1996

To study the effect of the pretension level in reconstructions of the anterior cruciate ligament ... more To study the effect of the pretension level in reconstructions of the anterior cruciate ligament (ACL) we examined 26 patients with isolated ACL insufficiency and intact Dacron ligament prosthesis at 4-year follow-up. The patients were divided into two groups of 13 each, based on pretension level applied at the reconstruction: in group I the ligament was pretensioned to 60 N and in group II to 40 N. The patients were evaluated by the Tegner and Lysholm scores, KT-1000 arthrometer measurements, and isokinetic muscle performance testing and were assessed by the Knee Ligament Standard Evaluation Form of the International Knee Documentation Committee. At followup there were no differences between the two groups in any of the evaluated parameters except for squatting ability. The two groups differed significantly (P < 0.01) with regard to the squatting score: 11 patients in group I had decreased squatting ability, and 6 of these were not able to squat beyond 90 ~ of flexion. In contrast, only 4 patients in group II had slightly impaired squatting ability. It is likely that this difference between the two groups is related to the magnitude of the pretension applied to the ligament prosthesis, and that the pretension exerts its influence through a change in the knee kinematics introduced at the time of the reconstruction.

Research paper thumbnail of Valgus bracing in patients with medial compartment osteoarthritis of the knee

Gait & Posture, 2007

A new valgus brace was evaluated in 15 patients with medial osteoarthritis of the knee and a varu... more A new valgus brace was evaluated in 15 patients with medial osteoarthritis of the knee and a varus leg axis. Significant improvement of pain and function were found after 6 weeks of brace treatment. Gait analysis showed that the brace had a tendency of lowering the peak varus moment about the knee. This effect was more profound in the presence of higher initial varus deformity angle of the knee. Furthermore, bracing led to a small decrease of knee extension at the end of the swing phase and an increase of walking velocity. The mechanisms identified by gait analysis in this study may be of clinical importance for future developments in brace treatment.

Research paper thumbnail of Valgus bracing in patients with medial compartment osteoarthritis of the knee: a gait analysis study of a new brace

Gait & posture, 2007

A new valgus brace was evaluated in 15 patients with medial osteoarthritis of the knee and a varu... more A new valgus brace was evaluated in 15 patients with medial osteoarthritis of the knee and a varus leg axis. Significant improvement of pain and function were found after 6 weeks of brace treatment. Gait analysis showed that the brace had a tendency of lowering the peak ...

Research paper thumbnail of Axial and torsional stability of supracondylar femur osteotomies: biomechanical comparison of the stability of five different plate and osteotomy configurations

Knee Surgery, Sports Traumatology, Arthroscopy, 2011

Purpose Little is known regarding the biomechanical stability and stiffness of implants and techn... more Purpose Little is known regarding the biomechanical stability and stiffness of implants and techniques used in supracondylar femur osteotomies (SCO). Therefore, fixation stability and stiffness of implants to bone was investigated under simulated physiological loading conditions using a composite femur model and a 3D motion-analysis system. Methods Five osteotomy configurations were investigated: (1) oblique medial closing-wedge fixated with an angle-stable implant; (2) oblique and (3) perpendicular medial closing-wedge, both fixated with an angled blade plate; and lateral opening-wedge fixated with (4) a spacer plate and (5) an angle-stable lateral implant. The motion measured at the osteotomy was used to calculate the stiffness and stability of the constructs. Results The least amount of motion and highest stiffness was measured in the medial oblique closing-wedge osteotomy fixated with the angled blade plate. The lateral opening-wedge techniques were less stable and had a lower stiffness compared with the medial; the oblique saw cuts were more stable and had a higher stiffness than the perpendicular. Conclusion This experimental study presents baseline data on the differences in the primary stability of bone-implant constructs used in SCO. The data in this study can be used as reference for future testing of SCO techniques. Furthermore, it is recommended that based on the differences found, the early postoperative rehabilitation protocol is tailored to the stability and stiffness of the fixation method used.

Research paper thumbnail of Distal femoral valgus osteotomy: bone healing time in single plane and biplanar technique

Strategies in Trauma and Limb Reconstruction

Varus deformity can be localized in the tibia, in the femur or in both. If varus deformity is loc... more Varus deformity can be localized in the tibia, in the femur or in both. If varus deformity is localized within the femur, it is mandatory to correct it in the femur. This report presents the technique and results of a consecutive case series of lateral uniplanar and biplanar closed-wedge valgus osteotomy of the distal femur for the treatment of varus deformity of the knee. Retrospectively, fifteen patients (sixteen knees) were identified. Indications for surgery varied from unloading an osteoarthritic medial compartment to reduction to symmetrical varus leg alignment. Pre-and post-operative X-rays, including a full leg radiograph, were assessed as well as bone healing time at follow-up intervals. Clinical outcome was assessed using different questionnaires. There were nine male and six female patients with a median age at surgery of 45 (±14) years. The mLDFA changed from 95.9°(±2.7°) preoperatively to 89.3°(±2.9°) post-operatively. Preoperative planning and the use of angle stable implants resulted in accurate corrections according to preoperative aims in all but one patient. At follow-up (mean, 40 months), the mean VAS score was 2.5 (±2.4) and the WOMAC score averaged 80 (±20). The mean bone healing time of biplanar osteotomies (4 ± 3 months) was shorter than in the uniplanar osteotomies (6 ± 3 months). Distal lateral closedwedge valgus osteotomy of the femur for the treatment of femoral varus deformities resulted in clinical improvement and accurate corrections in patients with different aims for correction. A biplanar osteotomy technique shortens bone healing time.