Deep peroneal nerve has a potential risk of injury during open-wedge high tibial osteotomy

Surgical strategy and complication management of osteotomy around the painful degenerative varus knee: ESSKA Formal Consensus Part II

PURPOSE

The purpose of the European consensus was to provide recommendations for the treatment of patients with a painful degenerative varus knee using a joint preservation approach. Part II focused on surgery, rehabilitation and complications after tibial or femoral correction osteotomy.

METHODS

Ninety-four orthopaedic surgeons from 24 countries across Europe were involved in the consensus, which focused on osteotomies around the knee. The consensus was performed according to the European Society for Sports Traumatology, Knee Surgery and Arthroscopy consensus methodology. The steering group designed the questions and prepared the statements based on the experience of the experts and the evidence of the literature. The statements were evaluated by the ratings of the peer-review groups before a final consensus was released.

RESULTS

The ideal hinge position for medial opening wedge high tibial osteotomy (MOW HTO) should be at the upper level of the proximal tibiofibular joint, and for lateral closing wedge distal femoral osteotomy (LCW DFO) just above the medial femoral condyle. Hinge protection is not mandatory. Biplanar osteotomy cuts provide more stability and quicker bony union for both MOW HTO and LCW DFO and are especially recommended for the latter. Osteotomy gap filling is not mandatory, unless structural augmentation for stability is required. Patient-specific instrumentation should be reserved for complex cases by experienced hands. Early full weight-bearing can be adopted after osteotomy, regardless of the technique. However, extra caution should be exercised in DFO patients. Osteotomy patients should return to sports within 6 months.

CONCLUSION

Clear recommendations for surgical strategy, rehabilitation and complications of knee osteotomies for the painful degenerative varus knee were demonstrated. In Part 2 of the consensus, high levels of agreement were reached by experts throughout Europe, under variable working conditions. Where science is limited, the collated expertise of the collaborators aimed at providing guidance for orthopaedic surgeons developing an interest in the field and highlighting areas for potential future research.

LEVEL OF EVIDENCE

Level II, consensus.

Open-wedge high tibial osteotomy with a slight valgus correction from neutral limb alignment achieves clinical improvements comparable with those for knees with varus deformity

PURPOSE

The effect of open-wedge high tibial osteotomy (OWHTO) on the preoperative neutral alignment of the knee is unknown. The purpose of this study was to clarify the clinical outcome of OWHTO with neutral alignment, defined as within 4 degrees of varus.

METHODS

This retrospective study included 72 knees with varus that underwent medial OWHTO. The knees were divided according to the preoperative hip-knee-ankle angle into a neutral alignment group (≤ 4° of varus alignment) and a varus alignment group (> 4° of varus alignment). The Knee Injury and Osteoarthritis Outcome Score (KOOS) and the Forgotten Joint Score-12 (FJS-12) were evaluated preoperatively and during at least 2 years of follow-up postoperatively.

RESULTS

There were no significant differences between the preoperative FJS-12 (17.9 versus 23.7; p = 0.16) and postoperative FJS-12 (57.3 versus 60.6; p = 0.52) or KOOS subscale scores (p > 0.05) in the neutral alignment group or the varus alignment group. Each group had a mean change in the KOOS subscale scores that exceeded the minimum clinically important difference.

CONCLUSION

The short-term clinical results of OWHTO for neutral alignment were as favourable as those for varus malalignment.

LEVEL OF EVIDENCE

IV.

High tibial osteotomy for medial meniscus posterior root tears in knees with moderate varus alignment can achieve favorable clinical outcomes

Purpose

Favorable clinical results have been reported following high tibial osteotomy (HTO) for medial meniscus posterior root tear (MMPRT) in knees with varus alignment. However, the effect on the preoperative neutral alignment of the knee is not known. This study sought to evaluate the clinical outcomes of medial open-wedge HTO for MMPRT with neutral alignment.

Methods

We retrospectively reviewed 119 medial open-wedge HTOs and analyzed 22 knees with MMPRT. The knees were divided according to the preoperative hip-knee-ankle angle into a moderate varus alignment group (≤4° of varus alignment) and a varus alignment group (> 4° of varus alignment). The Knee Injury and Osteoarthritis Outcome Score (KOOS) and Forgotten Joint Score-12 (FJS-12) values were evaluated preoperatively and at the latest follow-up. The healing status of MMPRT at the time of second-look arthroscopy, performed at a mean of 15.4 ± 4.2 months, was compared with that after the primary HTO.

Results

There were 11 knees in the moderate varus alignment group and 11 in the varus alignment group. In terms of perioperative patient-reported outcome measures, there was no significant difference in the preoperative or postoperative KOOS subscale score or FJS-12 score between the moderate varus and varus alignment groups. The healing rate was significantly higher in the moderate varus alignment group.

Conclusion

Favorable clinical results were obtained by medial open-wedge HTO in knees with MMPRT and moderate varus alignment in the short term. Surgeons should consider the indications for medial open-wedge HTO, even with moderate varus alignment, when planning treatment for MMPRT with persistent knee pain.

Level of evidence

IV

Supplementary Information

The online version contains supplementary material available at 10.1186/s40634-022-00504-9.

Biomechanical evaluation of combined proximal tibial osteotomy for varus knee osteoarthritis implanted novel designed plate system: Finite element analysis

BACKGROUND

Combined proximal tibial osteotomy (CPTO) is an innovative and effective procedure for correcting varus knee osteoarthritis (VKOA) with intra- and extra-articular deformity. Here, we designed a novel internal fixation plate system for CPTO and assessed the biomechanical strength of the bone-implant.

METHODS

Our newly designed CPTO internal fixation plate system included a specialized plate shape, combination holes, locking screw holes, screw position, and size of fixation. The biomechanical performance of this plate system in CPTO treatment was compared via finite element analysis (FEA) to traditional Tomofix devices implanted in the opening-wedge high tibial osteotomy (OWHTO), tibial condylar valgus osteotomy (TCVO), and CPTO.

RESULTS

The tibial wedge stiffness and displacement after CPTO implantation of the novel internal plate fixation increased by 9.6%, which was -65% higher than the CPTO with the Tomofix system. The average stress of the bone, plate, and screws in the CPTO implanted the novel designed plate system compared to the Tomofix system decreased by 12.7%, 1.9%, and 20.3 %, respectively. The device maximum stress and wedge stiffness after CPTO with the novel plate system versus traditional OWHTO and TCVO with the Tomofix system were 255.7 MPa, 204 MPa, 130.4 MPa, and 678.9 N/mm, 660.3 N/mm, 1626.0 N/mm, respectively.

CONCLUSIONS

The novel internal fixation plate system usage during CPTO exhibited similar bone-implant biomechanical strength, compared to OWHTO, but with enhanced construct stability.

Nerve branches to the anterior tibial artery: clinical application

INTRODUCTION

Arteries receive vascular branches (VBs) from peripheral nerves. VBs are thought to be involved in arterial constriction. Although the anterior tibial artery (ATA) receives VBs, information on their branching patterns and distribution areas remains limited. The aim of this study was to investigate the anatomical structures of the VBs reaching the ATA.

MATERIALS AND METHODS

Forty cadaver limbs were examined to assess the branching patterns and distribution areas of the VBs reaching the ATA.

RESULTS

The VBs reaching the ATA ramified from the deep fibular nerve (DFN), and the ATA received two or three VBs in each limb. The following mean distances from the head of fibula to the points at which the VBs reached the ATA were measured: all the VBs, 1st VB, 2nd VB and 3rd VB. The measurements were 51.5 ± 23.2 mm, 33.3 ± 3.7 mm, 53.3 ± 18.6 mm, and 72.2 ± 24.5 mm, respectively. In all limbs, the DFN and the ATA converged after the DFN branched into the 1^st VB. The 2^nd VB in 38 of 40 limbs and the 3^rd VB in 20 of 32 limbs were distributed in the ATA proximal to the convergence point of the ATA and the DFN.

CONCLUSIONS

These findings revealed that all VBs reaching the ATA ramified from the DFN in all limbs. The ATA received two or three VBs, and all the 1^st VBs distributed to the ATA proximal to the convergence point. This article is protected by copyright. All rights reserved.

Open Wedge High Tibial Osteotomy with Pes Anserinus Preservation and Insertion of Bone Substitutes

Biplanar open wedge high tibial osteotomy (OWHTO) has become common since the introduction of OWHTO-specific plates. However, the management of soft tissues, including skin, the pes anserinus, and the superficial medial collateral ligament (sMCL) release vary among surgeons. We introduce an OWHTO methodology that avoids pes incision and repair, uses bone substitute insertion into the opening gap and includes management of soft tissues to minimize complications. We adopted a reversed curved oblique incision to reduce the risk of saphenous nerve injury. We avoided pes incision, taking advantage of its posterior component force to allow it to function as a compressor of the ascending osteotomy site. The proximal component force of the pes provides compression between the bone substitute insertions and the proximal/distal cortices. This allows postoperative weight bearing to be distributed to the substitute, which may reduce the risk of implant failure. The sMCL is detached from the distal tibial attachment without cutting, enabling its return to its original position underneath the pes and to be repaired. This sMCL release with complete pes preservation may reduce the risk of deep infection or medial laxity during total knee arthroplasty conversion, and further reduce the risks of OWHTO.

[Correction of complex defomities around the Knee Joint]

Complex deformities around the knee joint are usually severe and have several aetiologies. They can be present in one or more planes, with variations in severity between planes. The occurrence and progression of the deformity can be influenced by local and systemic factors. Several types of osteotomies and fixation methods are available to correct these complex deformities. The selection of the osteotomy used to correct a deformity depends on the type of deformity, its severity and its aetiology. Therefore, precise planning taking into consideration the above factors is necessary to achieve the goal.

Early experience using patient-specific instrumentation in opening wedge high tibial osteotomy

PURPOSE

Patient-specific instruments (PSI) have been designed to improve the accuracy of performing opening-wedge high-tibial osteotomies (OW-HTO). This study aims to evaluate the lower limb alignment, by comparing pre-operative desired correction to post-operative achieved correction, the difference in surgical time and number of radiological exposures in OW-HTO using patient-specific instruments (PSI) versus conventional osteotomies and the specific and non-specific complications that occurred.

METHODS

We performed a single-centre, retrospective, observational study, including 25 consecutive patients undergoing OW-HTO using PSI, from January 2019 to October 2020.

RESULTS

Pre-operatively, the mean hip-knee angle (HKA) was 167°, the mean tibial slope was 7.9° and the mean medial proximal tibial angle (MPTA) was 82.5°. Post-operatively, the mean HKA was 182.2° (180.1-184.7°), the tibial slope was 6.5° (4.2-12.9°) and the MPTA was 92.8° (90.6-93°). In both coronal and sagittal plane, all knees were within 2° from the planned value. The mean tourniquet time, by which the surgical time was measured, was 40 minutes and the average number of intra-operative fluoroscopic images was 10 (range: 7-14), significantly less than when using conventional techniques.

CONCLUSIONS

The use of PSI in OW-HTO allows accurate achievement of the desired correction, while shortening the OR time. The number of radiological exposures is also decreased, in comparison with the conventional osteotomies.

Monocortical fixation for locking plate distal screws does not impair mechanical properties in open-wedge high tibial osteotomy

Background

The neurovascular bundle containing the deep peroneal nerve has a potential risk of injury during open-wedge high tibial osteotomy (OWHTO), particularly due to drilling for bicortical fixation at distal screw holes. Therefore, monocortical fixation is recommended for distal fixation of a long locking plate as long as good stability is ensured. The purpose of this study was to analyse the biomechanical properties of monocortical fixation of distal locking screws for OWHTO.

Methods

Three-dimensional models of bone and fixation materials simulating OWHTO were created using computed tomographic data of patients and material data of a T-shaped long locking plate and screws. Three of the four distal screws of the locking plate were chosen for a bicortical fixation or monocortical fixation procedure. In addition, loss of correction was assessed by measuring the medial proximal tibial angle (MPTA) in patients who underwent OWHTO with two bicortical and two monocortical distal fixation screws at 1 month and 1 year after surgery.

Results

No significant differences in stress were observed in either the normal or osteoporotic bone model between the monocortical and bicortical fixation models, including in the area of the lateral hinge at the osteotomy site.

Furthermore, there were no significant differences in MPTA between the early post-operative period and 1-year follow-up.

Conclusions

The monocortical fixation method for three distal screws of the locking plate did not worsen the mechanical properties of fixation for OWHTO using a long locking plate with four proximal and four distal screws. In actual surgery, the number of distal bicortical screws should be reduced based on the patient’s condition, taking into account the risk of lateral hinge fracture and unexpected surgical complications. Using at least two bicortical screws would be practical considering the various factors related to reduced fixing ability.