Realignment surgery as alternative treatment of varus and valgus ankle osteoarthritis

Analysis of radiologic parameters and clinical outcomes in supramalleolar osteotomy for varus ankle osteoarthritis: A novel method for evaluating ankle alignment

BACKGROUND

Solely relying on the tibial ankle surface (TAS) angle for determining the mechanical ankle axis might be insufficient. We introduce a novel method to determine the distance from the center of the talus to the tibial axis (TTD). This study aimed to investigate the association between clinical outcomes and radiological changes before and after supramalleolar osteotomy (SMO), including TAS angle, talar tilt (TT) angle, tibiotalar surface (TTS) angle and TTD.

METHODS

Seventy patients who received SMO were enrolled. Radiological changes were measured using weight-bearing anteroposterior imaging. The percentage of talar center displacement (TTDP) was calculated as the difference between postoperative and preoperative TTD, divided by talar width (TW). Clinical assessments were performed using the American Orthopedic Foot and Ankle Society ankle-hindfoot (AOFAS) scale. Differences in the aforementioned indicators before and after the operation were analyzed. We defined ΔAOFAS, ΔTAS, ΔTT and ΔTTS as the difference between postoperative and preoperative values.

RESULTS

ΔTTS correlated with ΔAOFAS (r = 0.40, p = 0.008), as did TTDP (r = 0.32, p = 0.035). No correlation was observed between ΔAOFAS and ΔTAS. In the comparison between groups, patients with a TTDP greater than 26.19 exhibited a significantly greater ΔAOFAS. The high intraclass correlation coefficient indicated good reliability of the novel method.

CONCLUSION

Solely relying on the TAS angle for tibial correction was insufficient. We found TTD as a novel method to evaluate mechanical ankle joint axis. TTDP and ΔTTS both positively correlated with ΔAOFAS, indicating the usefulness of these radiologic parameters.

Functional and radiographic assessments of post-traumatic asymmetrical ankle osteoarthritis treatment using supramalleolar osteotomies

PURPOSE

This study's objective is to assess the effectiveness of supramalleolar osteotomies (SMOT) in the treatment of asymmetrical ankle osteoarthritis in terms of the improvement in alignment assessed radiographically and its impact on symptoms measured by the American Orthopedic Foot and Ankle Society ankle-hindfoot score (AOFAS ankle-hindfoot score).

METHODS

Twelve patients participated in this prospective observational case series study. Standing anteroposterior, true lateral, and mortise views radiographs were taken. For preoperative planning, the lateral distal tibial angle (LDTA), talar tilt (TT), talocrural angle (TCA), and anterior distal tibial angle (ADTA) were all measured. A medial opening wedge osteotomy mainly was used to treat the varus arthritis ankle. A further oblique fibular osteotomy is frequently necessary.

RESULTS

The male-to-female ratio was 3:1, and the mean age of the patients was 26.25 ± 13.032 years. There were highly statistically significant differences between pre-and post-operative AOFAS ankle-hindfoot score (p < 0.001). Statistically significant differences concerning ankle range of motion (p = 0.002, < 0.001) of dorsiflexion and planter flexion were detected. Comparison between pre-and post-operative patients' radiology characteristics shows statistically significant differences concerning TT (p = 0.016) and LDTA (p = 0.046).

CONCLUSION

SMOT is very effective in the treatment of post-traumatic ankle osteoarthritis and postpones ankle fusion or total ankle replacements. This surgery significantly improves functional and radiological outcomes as well as the range of motion in the ankle. Meticulous preoperative planning by radiological measurements of different angles around the ankle is considered the crucial factor in success of that operation.

Pathophysiology of abnormal compensation ability of the subtalar joint in the varus knee

BACKGROUND

In recent years, the involvement of the compensation ability of the subtalar joint in lower extremity alignment has been reported. We previously showed that hindfoot alignment angle (HAA) is an indicator of compensation ability of the subtalar joint. The abnormal compensation ability of the subtalar joint was defined by the mobility of the subtalar joint, and evaluation of the mobility of the subtalar joint may help to further clarify the pathophysiology of abnormal compensation ability of the subtalar joint. This study was performed to evaluate the mobility of the subtalar joint and clarify the pathophysiology of abnormal compensation ability of the subtalar joint in the varus knee.

METHODS

Seventy-two knees of 72 patients aged ≥40 years with varus knee were included in this study. Preoperative radiographs were used for measurement of this study parameters. Based on our previous study, we defined HAA of ≥15.9°as abnormal compensation ability of the subtalar joint. The patients were divided into an abnormal group (A-group) and normal group (N-group). All measurement parameters were compared between the groups, and correlations between the HAA and each measurement parameter were analyzed.

RESULTS

The weight-bearing hindfoot angle (WBHA) (p < 0.001) and non-weight-bearing hindfoot angle (non-WBHA) (p = 0.003), were significantly greater in the A-group than in the N-group. Conversely, the ratio of change in hindfoot alignment (p = 0.006), were significantly smaller in the A-group than in the N-group. The HAA was positively correlated with WBHA (r = 0.66) and non-WBHA (r = 0.43) and negatively correlated with the ratio of change in hindfoot alignment (r = -0.32).

CONCLUSIONS

The pathophysiology of abnormal compensation ability of the subtalar joint in the varus knee is thought to involve a state of increased valgus of hindfoot alignment and an inability to move into normal hindfoot alignment.

LEVEL OF EVIDENCE

Level Ⅲ, retrospective study.

The Unloading Effect of Supramalleolar Versus Sliding Calcaneal Osteotomy for Treatment of Osteochondral Lesions of the Medial Talus: A Biomechanical Study

Background

In patients with osteochondral lesion, defects of the medial talus, or failed cartilage surgery, a periarticular osteotomy can unload the medial compartment.

Purpose

To compare the effects of supramalleolar osteotomy (SMOT) versus sliding calcaneal osteotomy (SCO) for pressure redistribution and unloading of the medial ankle joint in normal, varus-aligned, and valgus-aligned distal tibiae.

Study Design

Controlled laboratory study.

Methods

Included were 8 cadaveric lower legs with verified neutral ankle alignment (lateral distal tibial angle [LDTA] = 0°) and hindfoot valgus within normal range (0°-10°). SMOT was performed to modify LDTA between 5° valgus, neutral, and 5° varus. In addition, a 10-mm lateral SCO was performed and tested in each position in random order. Axial loading (700 N) of the tibia was applied with the foot in neutral alignment in a customized testing frame. Pressure distribution in the ankle joint and subtalar joint, center of force, and contact area were recorded using high-resolution Tekscan pressure sensors.

Results

At neutral tibial alignment, SCO unloaded the medial joint by a mean of 10% ± 10% or 66 ± 51 N (P = .04) compared with 6% ± 12% or 55 ± 72 N with SMOT to 5° valgus (P = .12). The achieved deload was not significantly different (ns) between techniques. In ankles with 5° varus alignment at baseline, SMOT to correct LDTA to neutral insufficiently addressed pressure redistribution and increased medial load by 6% ± 9% or 34 ± 33 N (ns). LDTA correction to 5° valgus (10° SMOT) unloaded the medial joint by 0.4% ± 14% or 20 ± 75 N (ns) compared with 9% ± 11% or 36 ± 45 N with SCO (ns). SCO was significantly superior to 5° SMOT (P = .017) but not 10° SMOT. The subtalar joint was affected by both SCO and SMOT, where SCO unloaded but SMOT loaded the medial side.

Conclusion

SCO reliably unloaded the medial compartment of the ankle joint for a neutral tibial axis. Changes in the LDTA by SMOT did not positively affect load distribution, especially in varus alignment. The subtalar joint was affected by SCO and SMOT in opposite ways, which should be considered in the treatment algorithm.

Clinical Relevance

SCO may be considered a reliable option for beneficial load-shifting in ankles with neutral alignment or 5° varus malalignment.

The Role of Supramalleolar Osteotomies in Ankle Arthritis

The supramalleolar osteotomy (SMO) is a joint-preserving surgical procedure that allows realignment of the ankle joint in severe deformity secondary to arthritis. This osteotomy realigns the mechanical axis to provide better weight distribution through the ankle joint. With an aligned mechanical axis, the overloaded asymmetric ankle joint will shift toward the preserved joint area in a valgus or varus ankle joint. The SMO also can be used via a staged approach to correct severe deformity in an end-stage arthritic ankle before total ankle arthroplasty to optimize the implant's longevity and improve overall functional outcomes.

Supramalleolar osteotomies for ankle arthritis: a systematic review

INTRODUCTION

We investigated the mid-term outcomes of supramalleolar osteotomies regarding "survivorship" [before ankle arthrodesis (AA) or total ankle replacement (TAR)], complication rate and adjuvant procedures required.

MATERIAL AND METHODS

PubMed, Cochrane and Trip Medical Database were searched from January 01, 2000. Studies reporting on SMOs for ankle arthritis, in minimum of 20 patients aged 17 or older, followed for a minimum of two years, were included. Quality assessment was performed with the Modified Coleman Methodology Score (MCMS). A subgroup analysis of varus/valgus ankles was performed.

RESULTS

Sixteen studies met the inclusion criteria, with 866 SMOs in 851 patients. Mean age of patients was 53.6 (range 17-79) years, and mean follow-up was 49.1 (range 8-168) months. Of the arthritic ankles (646 ankles), 11.1% were classified as Takakura stage I, 24.0% as stage II, 59.9% as stage III and 5.0% as stage IV. The overall MCMS was 55.2 ± 9.6 (fair). Eleven studies (657 SMOs) reported on "survivorship" of SMO, before arthrodesis (2.7%), or total ankle replacement (TAR) (5.8%) was required. Patients required AA after an average of 44.6 (range 7-156) months, and TAR after 36.71 (range 7-152) months. Hardware removal was required in 1.9% and revision in 4.4% of 777 SMOs. Mean AOFAS score was 51.8 preoperatively, improving to 79.1 postoperatively. Mean VAS was 6.5 preoperatively and improved to 2.1 postoperatively. Complications were reported in 5.7% (44 out of 777 SMOs). Soft tissue procedures were performed in 41.0% (310 out of 756 SMOs), whereas concomitant osseous procedures were performed in 59.0% (446 out of 756 SMOs). SMOs performed for valgus ankles failed in 11.1% of patients, vs 5.6% in varus ankles (p < 0.05), with disparity between the different studies.

CONCLUSIONS

SMOs combined with adjuvant, osseous and soft tissue, procedures, were performed mostly for arthritic ankles of stage II and III, according to the Takakura classification and offered functional improvement with low complication rate. Approximately, 10% of SMOs failed and patients required AA or TAR, after an average of just over 4 years (50.5 months) after the index surgery. It is debatable whether varus and valgus ankles treated with SMO reveal different success rates.

Evaluation of clinico-radiological outcome of fibular valgization osteotomy with supra-malleolar osteotomy in patients with ankle osteoarthritis

PURPOSE

There are controversies about combining distal tibia medial opening-wedge osteotomy (DTMO) with fibular valgization osteotomy (FVO) when performing supramalleolar osteotomy (SMO) for medial ankle osteoarthritis. This study aimed to assess the effect of FVO on the coronal translation of the mechanical axis by comparing the improvement of radiological indices after DTMO with and without FVO.

METHODS

Forty-three ankles (mean follow-up: 42.0 months) were reviewed after SMO. Among them, 35/43 (81.4%) underwent DTMO with FVO, while 8/43 (18.6%) underwent DTMO only. To evaluate the effect of FVO radiologically, the medial gutter space (MGS) and talus centre migration (TCM) were measured.

RESULTS

Post-operatively, MGS and TCM were not significantly different after DTMO only and DTMO with FVO. However, the improvement of MGS was significantly higher in the combined FVO group (0.8 mm (standard deviation [SD] 0.8 mm) vs. 1.5 mm (SD 0.8 mm); p = 0.015). More lateral translation of the talus was achieved in the FVO group (5.1 mm (SD 2.3 mm) vs. 7.5 mm (SD 3.0 mm); p = 0.033). However, the changes in the MGS and TCM were not significantly correlated with the clinical outcomes (p > 0.05).

CONCLUSION

Our radiological evaluation confirmed a significant medial gutter space widening and lateral talar translation after the addition of FVO. The SMO with fibular osteotomy allows greater shifting of the talus and, therefore, the weight-bearing axis.

Value of postoperative computed tomography for the diagnosis of lateral hinge fracture in medial opening-wedge supramalleolar osteotomy

INTRODUCTION

It remains unclear whether computed tomography (CT) is superior to plain radiography in detecting lateral hinge fractures after medial opening-wedge supramalleolar osteotomy (SMO) of the ankle joint. This study aimed to evaluate the disparity between postoperative plain radiography and CT in detecting lateral hinge fractures after medial opening-wedge SMO and to identify the predictive factors of lateral hinge fractures.

MATERIALS AND METHODS

This retrospective study included 39 patients who underwent medial opening-wedge SMO. The immediate postoperative plain radiography and CT scan images were retrieved, and the presence of lateral hinge fractures was independently determined. Depending on the fracture gap, the lateral hinge fractures were subclassified as stable (gap < 2 mm) or unstable (gap ≥ 2 mm) fractures. To investigate the predictive factors, the cases were divided based on diagnostic tools such as plain radiography and CT.

RESULTS

The incidence of lateral hinge fractures was 48.7% (19/39) on plain radiographs and 61.5% (24/39) on CT scans. Five cases of lateral hinge fractures additionally detected on CT scans were stable fractures, and all had been classified as no fracture on plain radiographs. The unstable fractures that had been subclassified based on plain radiographs did not change on CT scans. None of the variables were associated with the presence of lateral hinge fractures on plain radiographs and CT scans.

CONCLUSIONS

Postoperative CT after medial opening-wedge SMO has no additional diagnostic value if the lateral hinge fracture has already been diagnosed on plain radiography. Therefore, postoperative CT is only recommended when lateral hinge fractures are not visible on plain radiographs.

Correction of ankle varus deformity using patient-specific dome-shaped osteotomy guides designed on weight-bearing CT: a pilot study

BACKGROUND

Dome-shaped supramalleolar osteotomies are a well-established treatment option for correcting ankle deformity. However, the procedure remains technically demanding and is limited by a two-dimensional (2D) radiographic planning of a three-dimensional (3D) deformity. Therefore, we implemented a weight-bearing CT (WBCT) to plan a 3D deformity correction using patient-specific guides.

METHODS

A 3D-guided dome-shaped supramalleolar osteotomy was performed to correct ankle varus deformity in a case series of five patients with a mean age of 53.8 years (range 47-58). WBCT images were obtained to generate 3D models, which enabled a deformity correction using patient-specific guides. These technical steps are outlined and associated with a retrospective analysis of the clinical outcome using the EFAS score, Foot and Ankle Outcome Score (FAOS) and visual analog pain scale (VAS). Radiographic assessment was performed using the tibial anterior surface angle (TAS), tibiotalar angle (TTS), talar tilt angle (TTA), hindfoot angle (HA), tibial lateral surface angle (TLS) and tibial rotation angle (TRA).

RESULTS

The mean follow-up was 40.8 months (range 8-65) and all patients showed improvements in the EFAS score, FAOS and VAS (p < 0.05). A 3-month postoperative WBCT confirmed healing of the osteotomy site and radiographic improvement of the TAS, TTS and HA (p < 0.05), but the TTA and TRA did not change significantly (p > 0.05).

CONCLUSION

Dome-shaped supramalleolar osteotomies using 3D-printed guides designed on WBCT are a valuable option in correcting ankle varus deformity and have the potential to mitigate the technical drawbacks of free-hand osteotomies.

LEVEL OF EVIDENCE

Level 5 case series.

Lower limb alignment in patients with primary valgus ankle arthritis: A comparative analysis with patients with varus ankle arthritis and healthy controls

BACKGROUND

While it is commonly acknowledged that the combined effect of lower limb orientation and ankle and hindfoot alignment play a fundamental role in ankle arthritis, supramalleolar/lower limb alignment has received less attention in valgus ankle arthritis. The purpose of this study was to analyze the lower limb alignment of patients with valgus ankle arthritis with primary origin, compared to that of varus ankle arthritis and normal controls. We hypothesized that patients with valgus ankle arthritis would have the opposite pattern of lower limb alignment as those with varus ankle arthritis.

METHODS

A retrospective radiographic analysis was performed on 61 patients (62 ankles, mean age, 59.3 ± 12 years) with primary valgus ankle arthritis. On preoperative radiographs, seven parameters, including talar tilt angle, medial distal tibial angle (MDTA), talar center migration, anterior distal tibial angle, talo-first metatarsal (Meary's) angle, hindfoot moment arm (HMA), and mechanical axis deviation (MAD), were measured and compared to those of primary varus ankle arthritis (n = 55; mean age, 59.7 ± 8.1 years) and control patients (n = 59; mean age, 29.3 ± 7.3 years).

RESULTS

The valgus group had a significantly lower mean MDTA than the control group (p < 0.0001), indicating a varus distal tibial plafond in comparison to the control group. Meary's angle and HMA were significantly lower in the valgus group compared to the varus group (p < 0.05 and p < 0.0001, respectively), indicating a lower medial longitudinal arch and valgus hindfoot alignment. On whole limb radiographs, the valgus group showed a greater MAD than the control group, indicating varus lower limb alignment (p < 0.05). However, the MAD did not differ significantly between the valgus and varus groups (p = 0.7031).

CONCLUSION

Our findings indicate that a significant proportion of ankles with primary valgus arthritis have a varus tibial plafond and a varus lower limb mechanical axis. This study contributes to our understanding of primary valgus ankle arthritis and suggests that lower limb alignment should be analyzed and considered throughout valgus ankle arthritis realignment procedures.

Influence of hindfoot alignment on postoperative lower limb alignment in medial opening wedge high tibial osteotomy

INTRODUCTION

We have experienced unexpected under-correction after medial opening wedge high tibial osteotomy (MOWHTO). Although the tibia was corrected accurately, the postoperative mechanical axis (MA) was less than 57%. The purpose of this study was to evaluate the relationship between hindfoot alignment and postoperative lower limb alignment, and to reveal whether hindfoot alignment affects lower limb alignment after MOWHTO. Our hypothesis was that hindfoot alignment influences the postoperative MA in MOWHTO.

MATERIALS AND METHODS

This study was a retrospective comparative study. The study cohort comprised 43 knees in 43 patients who underwent MOWHTO and had standing long-leg anteroposterior view and hindfoot alignment view radiographs taken preoperatively and at 3 months postoperatively. To evaluate the hindfoot alignment, the absolute value of the ankle joint line orientation relative to the ground was added to the absolute value of the hindfoot angle. We defined a postoperative MA of 57-67% as acceptable correction (A group) and a MA of < 56% as under-correction (U group). The two groups were analyzed to identify factors that affected postoperative limb alignment.

RESULTS

The preoperative hindfoot alignment angle was significantly larger in the U group than the A group. The preoperative hindfoot alignment angle was a significant predictive factor of the postoperative MA, and the cut-off value that distinguished under-correction from acceptable correction was 15.9 degrees.

CONCLUSION

Abnormal hindfoot alignment is one of the causes of under-correction after MOWHTO. Attention should be paid to the preoperative ankle joint line orientation relative to the ground and hindfoot angle. If the preoperative hindfoot alignment angle is ≥ 15.9 degrees, surgeons should reconsider the operative procedure and correction angle.

LEVEL OF EVIDENCE

Therapeutic level III, retrospective study.

Short-Term Clinical Outcomes Following Total Ankle Arthroplasty Without Concomitant Osteotomy in Ankles with Severe Preoperative Varus Deformity: Comparison to Ankles with Preoperative Neutral Alignment

BACKGROUND

It remains controversial whether satisfactory outcomes can be obtained following total ankle arthroplasty (TAA) without osteotomy in patients with severe varus ankle deformities. This study aimed to examine outcomes following TAA without concomitant osteotomies in patients with severe varus ankle alignment by comparing them with those in patients with neutral alignment.

METHODS

Fifty-one patients (53 ankles; mean age, 71.4 ± 5.6 years) who underwent TAA using the TNK ankle prosthesis were examined (mean follow-up, 36.8 ± 17.8 months). Patients were allocated into groups according to the preoperative talar tilt (TT) angle: the neutral group (preoperative TT angle <10°; n = 37) and the varus group (preoperative TT angle ≥10°; n = 16). Outcome measures, including the Japanese Society for Surgery of the Foot scale, Self-Administered Foot Evaluation Questionnaire, ankle range of motion, and radiographic parameters, were assessed before surgery and at the final follow-up.

RESULTS

Significant improvements were observed in clinical and radiographic outcomes in both groups after surgery. Postoperative Japanese Society for Surgery of the Foot scale and subscale scores of pain and shoes in the Self-Administered Foot Evaluation Questionnaire were not significantly different between the groups, whereas subscale scores of function, social, and health were greater in the varus group than in the neutral group at the final follow-up. Radiographic parameters, including TT angle and tibial axis-medial malleolus (TMM) angle, improved postoperatively and were not significantly different between the neutral (mean TT angle, 0.5 ± 0.7°; mean TMM angle, 16.0 ± 4.6°) and varus (meanTT angle, 0.4 ± 0.7°; meanTMM angle, 17.0 ± 5.3°) groups at the final follow-up. To achieve neutral alignment, adjunctive procedures were required more often in the varus group.

CONCLUSIONS

Outcomes of TAA using the TNK ankle prosthesis were favorable in patients with severe varus ankle and in those with neutral ankle without concomitant osteotomy. Satisfactory outcomes could be achieved in patients with severe varus ankle alignment after TAA without concomitant osteotomy.

Is there an optimal degree of correction for ankle varus deformity after supramalleolar osteotomy? A systematic review

BACKGROUND

There is no consensus on the angle targeted for in varus ankle deformity after supramalleolar osteotomy (SMOT). The aim of this study was to investigate which obtained correction has the best clinical outcome after valgus SMOT.

METHODS

A systematic review according PRISMA guidelines was conducted with studies being eligible for inclusion when published in English, German or Dutch, patients older than 18 years at study entrance, primary or posttraumatic varus ankle osteoarthritis, using any valgus SMOT technique, describing radiological alignment and clinical outcome at baseline and after at least 12 months follow-up. Risk of bias was assessed using the McMaster University Occupational Therapy Evidence-Based Practice Research Group quality assessment tool. The electronical databases PubMed, EMBASE and Cinahl were used as data sources. Included cohorts were categorized according to the mean obtained medial distal tibia angle (MDTA; ranged between 87° and 100°). A linear mixed effect model was used for individual patient data to assess the association between the MDTA and the (difference in) clinical outcome.

RESULTS

Thirty studies including 33 patient cohorts with 922 ankles were identified. At a mean follow-up of 4 years no differences in clinical outcome between correction categories were found. Individual data of 34 ankles showed no relationship between obtained MDTA and clinical outcome either.

CONCLUSION

This review could not demonstrate an optimal degree of correction after valgus SMOT. Results were hampered by biased low quality studies and the widespread use of unreliable 2D alignment measures such as the MDTA.

General Considerations About Foot and Ankle Arthrodesis. Any Way to Improve Our Results?

Nonunion and adjacent joint osteoarthritis (OA) are known complications after a fusion procedure, and foot and ankle surgeons are commonly exposed to such disabling complications. Determining who is at risk of developing nonunion is essential to reducing nonunion rates and improving patient outcomes. Several evidenced-based modifiable risk factors related to adverse outcomes after foot and ankle arthrodesis have been identified. Patient-related risk factors that can be improved before surgery include smoking cessation, good diabetic control (HbAc1 <7%) and vitamin D supplementation. Intraoperatively, using less invasive techniques, avoiding joint preparation with power tools, using bone grafts or orthobiologics in more complex cases, high-risk patients, nonunion revision surgeries, and filling in bone voids at the arthrodesis site should be considered. Postoperatively, pain management with NSAIDs should be limited to a short period (<2 weeks) and avoided in high-risk patients. Furthermore, early postoperative weight-bearing has shown to be beneficial, and it does not seem to increase postoperative complications. The incidence of surrounding joint OA after foot and ankle fusion seems to increase progressively with time. Owing to its progression and high probability of being symptomatic, patients must be informed consequently, as they may require additional joint fusions, resulting in further loss of ankle/foot motion. In patients with symptomatic adjacent joint OA and unsatisfactory results after an ankle arthrodesis, conversion to total ankle arthroplasty (TAA) has become a potential option in managing these complex and challenging situations.

Outcomes of intermediate stage varus ankle arthritis treated by supramalleolar osteotomy

OBJECTIVE

To evaluate the outcomes of intermediate stage varus ankle arthritis treated by supramalleolar osteotomy.

METHODS

Clinical data of 57 patients with varus arthritis who underwent supramalleolar osteotomy at our hospital between March 2018 and December 2019 were retrospectively analyzed. The patients were grouped according to the Takakura classification, and assessed using the American Orthopaedic Foot and Ankle Society (AOFAS) Ankle-Hindfoot Score and the Visual Analogue Score (VAS). Tibial anterior surface (TAS) angle and talar tilt (TT) angle were measured at the weight-bearing anteroposterior view. Tibial lateral surface (TLS) angle was measured at the weight-bearing lateral view. The differences in the above indicators of patients with different stages of varus ankle arthritis before and after treatment were analyzed.

RESULTS

The patients were followed up for an average of 31.9 ± 5.8 months. Upon the last follow-up, the AOFAS score was 84.1 ± 9.7, the VAS score 2.2 ± 1.3, the TAS angle 92.4 ± 5.5°, the TLS angle 79.3 ± 5.3°, and the TT angle 3.7±3.4°, which were significantly different from the preoperative levels (64.2 ± 14.6, 4.5 ± 1.8, 80.5 ± 6.7°, 74.9 ± 4.6°, and 5.2 ± 64.1°, respectively) (p < .05). There were significant differences in AOFAS and VAS scores before surgery and upon the last follow-up in each group (p < .05). The postoperative TT angle was significantly different from the preoperative level in stage IIIb patients (p = .003).

CONCLUSIONS

Supramalleolar osteotomy achieved good short-to mid-term clinical outcomes for intermediate stage varus ankle arthritis. This procedure could significantly improve the TAS and TLS angles of the patients at any stage and the TT angle of stage IIIb patients.

The use of three-dimensional biometric Foot and Ankle Offset to predict additional realignment procedures in total ankle replacement

BACKGROUND

Decision to perform associated corrective alignment procedures in patients undergoing total ankle replacement (TAR) is commonly made intraoperatively. The Foot and Ankle Offset (FAO) can evaluate multiplanar deformity and be an effective instrument in surgical planning. This study objective was to assess the ability of this tool to predict the need for additional realignment procedures at the time of TAR.

METHODS

In this retrospective study, we enrolled 21 patients who underwent TAR and had preoperative WBCT studies. Two independent and blinded observers calculated the preoperative FAO using dedicated software. FAO measurements were compared between the different alignment groups (physiological alignment, valgus and varus). A multivariate regression analysis was used to assess the correlation between performed realignment procedures and FAO values.

RESULTS

Mean preoperative FAO was 4.4% (95%CI = 1.4-7.5). The number of osseous realignment procedures needed was found to correlate positively and significantly with FAO (p = .001). The number of osseus procedures needed was significantly higher in patients with valgus malalignment (p = .009). Patients with valgus malalignment needing a medial column procedure had a relative risk of 6.3 when compared to varus malalignment patients (p = .02).

CONCLUSION

The number of additional bony realignment procedures performed at the time of TAR significantly correlated with preoperative FAO and that the number of osseus procedures needed was significantly higher in patients with valgus malalignment. Such biometric tools may enhance the preoperative assessment and surgical planning for patients undergoing TAR, with the potential to optimize surgical outcomes.

Reconstructive Surgery and Joint-Sparing Surgery in Valgus and Varus Ankle Deformities: A Comprehensive Review

Osteoarthritis (OA) of the ankle affects about 1% of the world’s adult population, causing an important impact on patient lives and health systems. Most patients with ankle OA can show an asymmetrical wear pattern with a predominant degeneration of the medial or the lateral portion of the joint. To avoid more invasive ankle joint sacrificing procedures, joint realignment surgery has been developed to restore the anatomy of the joints with asymmetric early OA and to improve the joint biomechanics and symptoms of the patients. This narrative, comprehensive, all-embracing review of the literature has the aim to describe the current concepts of joint preserving and reconstructive surgery in the treatment of the valgus and varus ankle early OA, through an original iconography and clear indications and technical notes.

Supramalleolar Osteotomy for Ankle Varus Deformity Alters Subtalar Joint Alignment

BACKGROUND

Although correction of ankle and hindfoot deformity after supramalleolar osteotomy has been investigated extensively, the specific effect on the subtalar joint alignment remains elusive. This can be attributed to the limitations of 2-dimensional measurements, which impede an exact quantification of the 3-dimensional subtalar joint alignment. Therefore, we determined both the ankle, hindfoot, and subtalar joint alignment before and after supramalleolar osteotomy using autogenerated 3-dimensional measurements based on weightbearing CT imaging.

METHODS

Twenty-nine patients with a mean age of 50.4±10.6 years were retrospectively analyzed in a pre-post study design using weightbearing CT. Inclusion criteria were correction of ankle varus deformity by an opening wedge (n = 22) or dome osteotomy (n = 7). Exclusion criteria consisted of an additional inframalleolar arthrodesis or osteotomy. Corresponding 3-dimensional bone models were reconstructed to compute following autogenerated measurements of the ankle- and hindfoot alignment: tibial anterior surface (TAS), tibiotalar surface (TTS), talar tilt (TT) angle, hindfoot angle (HA). In addition, the talocalcaneal angle (TCA) in the axial (TCA_ax), sagittal (TCA_sag), and coronal (TCA_cor) plane were measured to assess the subtalar joint alignment.

RESULTS

The preoperative radiographic parameters of the ankle joint alignment (TAS=88±4 degrees, TTS=82±7 degrees, TT=5.8±4.9 degrees) improved significantly relative to their postoperative equivalents (TAS = 93±5 degrees, TTS = 88±7 degrees, TT=4.2±4.5 degrees; P < .05). The following radiographic parameters of the hindfoot and subtalar joint alignment improved significantly from preoperatively (8.7±8.9 degrees, TCA_ax = 41±10 degrees, TCA_sag = 48±10 degrees) to postoperatively (HA=4.5±8.6 degrees, TCA_ax = 38±9 degrees, TCA_sag = 44±11 degrees; P < .05). No significant differences could be detected in the coronal plane alignment of the subtalar joint (TCA_cor) pre- compared to postoperatively (P > .05).

CONCLUSION

This study quantified the 3-dimensional ankle, hindfoot, and subtalar joint alignment after a solitary supramalleolar osteotomy. We found alterations in the subtalar joint alignment, which occurred by 2 to 3 degrees in each anatomic plane. However, before recommendations can be given related to inframalleolar procedures in conjunction to supramalleolar osteotomies, further studies on the variation of subtalar joint alignment change are needed.

Evaluation of the hindfoot alignment before and after total knee arthroplasty

BACKGROUND

Open wedge high tibial osteotomy (OWHTO) and total knee arthroplasty (TKA) alter the ankle joint line obliquity (AJLO) to be more horizontal relative to the ground and aligns the valgus subtalar joint (SJ) neutrally. A previous study of the hindfoot alignment angle (HAA) showed that lower limb alignment after OWHTO becomes under-corrected because of abnormal compensation by the SJ. However, because TKA can exclude effects of femorotibial joint instability, analysis of a post-TKA cohort enables a more accurate evaluation of SJ compensation than analysis of a post-OWHTO cohort. In the present study, we performed radiographic evaluations before and after TKA to analyze SJ compensation.

METHODS

Lower limb and hindfoot alignment were measured on plain radiographs in 46 patients (48 knees) who underwent TKA in our department. The patients were divided into Group A (postoperative AJLO within ±1°) and Group B (postoperative AJLO greater than ±1°), and various parameters were compared between the groups. The preoperative HAA that resulted in an abnormal postoperative AJLO was investigated.

RESULTS

Group A had a significantly smaller preoperative HAA (p = 0.03) and postoperative HAA (p < 0.01) than Group B. Differences in the preoperative HAA between the two groups showed a cut-off value of 9.06°.

CONCLUSION

Patients with an HAA of more than 9.06° are likely to have abnormal hindfoot compensation.

Plain Radiographs Underestimate Varus Deformity of the Tibial Plafond

Understanding plain radiograph in association with 3-dimensional (3D) morphology of the ankle is essential for treatment about varus ankle osteoarthritis (OA). The aims of this study were to investigate whether the alignment of the tibial plafond as determined on plain radiograph reflected the alignment of the tibial plafond on computed tomography (CT) in varus ankle OA and whether the alignment of the tibial plafond changed as the OA progressed. The 3D CT and plain radiographs from 101 ankles with varus ankle OA were analyzed and compared with 40 ankles in control group. The tibial plafond was assessed in the coronal and sagittal planes using 3D CT. The medial angle between the vertical line and the tibial plafond was measured on 3 different coronal plane CT images which was anterior, middle and posterior area of the tibial plafond. The medial distal tibial angle on plain radiograph reflected the posterior area of the tibial plafond on CT. The amount of varus angulation on CT was larger in anterior and middle area of the tibial plafond than the posterior area. There was a difference in the degree of varus of the tibial plafond between control group and OA patients; however, there was no difference among patients in different stages of varus ankle OA. Weightbearing plain radiographs underestimate the varus deformity in anterior and middle area of the tibial plafond and there is no significant difference in deformity of the tibial plafond among patients in different stages of varus ankle OA.

Outcomes of oblique supramalleolar osteotomy without fibular osteotomy for congruent- and incongruent-type medial ankle arthritis

BACKGROUND

Although high talar tilt and ankle mortise incongruence are risk factors for supramalleolar osteotomy (SMO), no study on lateral talofibular joint congruence exists. We aimed to evaluate the outcomes of oblique SMO without fibular osteotomy for medial ankle arthritis and compare them according to the lateral talofibular joint congruity.

METHODS

Forty-eight ankles were retrospectively reviewed and divided according to preoperative talofibular joint congruity (congruent, 22 [45.8%] vs. incongruent, 26 [54.2%]).

RESULTS

The mean VAS score, AOFAS score, and modified Takakura stage were significantly improved. No significant differences were noted in clinical outcomes, but the mean postoperative tibiotalar angle and difference between the upper and lower talofibular gaps were significantly different in both groups (p = 0.004 and p = 0.009, respectively). The mean Takakura stage at 1 and 2 years after surgery was higher in the incongruent group (p = 0.013, p = 0.012).

CONCLUSION

This procedure was effective against early- to mid-stage medial ankle arthritis. Radiographic arthritic grade changed according to the talofibular joint congruity.

Effect of four combined procedures to achieve inframalleolar correction for advanced varus ankle arthritis

A man in his early 60s with Takakura stage IIIB varus ankle arthritis underwent four combined procedures (Dwyer's osteotomy with lateral displacement, superficial/deep deltoid ligament release, anterior talofibular ligament/calcaneofibular ligament reconstruction with suture tape augmentation and posterior tibial tendon lengthening). Decreased talar tilt and talar centre lateral shifting and improved hindfoot varus were observed 2 years postoperatively. Also, excellent clinical outcome could be achieved.

Joint-Preserving Surgery in Varus Ankle Osteoarthritis

Ankle deformity is a disabling condition especially if concomitant with osteoarthritis (OA). Varus ankle OA is one of the most common ankle OA deformities. This deformity usually leads to unequal load distribution in the ankle joint and decreases joint contact surface area, leading to a progressive degenerative arthritic situation. Varus ankle OA might have multiple causative factors, which might present as a single isolated factor or encompassed together in a single patient. The etiologies can be classified as post-traumatic (e.g., after fractures and lateral ligament instability), degenerative, systemic, neuromuscular, congenital, and others. Treatment options are determined by the degree of the deformity and analyzing the pathology, which range from the conservative treatments up to surgical interventions. Surgical treatment of the varus ankle OA can be classified into two categories, joint-preserving surgery (JPS) and joint-sacrificing surgery (JSS) as total ankle arthroplasty and ankle arthrodesis. JPS is a valuable treatment option in varus ankle OA, which should not be neglected since it has showed a promising result, optimizing biomechanics and improving the survivorship of the ankle joint.

Relationship between talofibular impingement and increased talar tilt in incongruent varus ankle osteoarthritis

PurposeThis study aimed to evaluate the relationship between talofibular impingement and increased talar tilt in incongruent varus ankle osteoarthritis. Methods: Incongruent varus ankle osteoarthritis was defined as a talar tilt of more than 4° on standard ankle anteroposterior radiographs. We retrospectively reviewed 30 patients with unilateral incongruent varus ankle osteoarthritis with normal alignment of the contralateral ankle. All patients underwent bilateral weightbearing computed tomography and standing plain radiographs. The talar tilt and the distance between the talar lateral process and lateral malleolar tip were measured from a standing ankle anteroposterior radiograph of both sides. Talar and fibular spurs were assessed on the coronal and axial views of weightbearing computed tomography. After simulating the correction of the talar tilt in varus ankle osteoarthritis, talofibular bony impingement was reassessed. Results: On the varus side, the distance between the talar lateral process and the lateral malleolar tip was significantly shorter than that on the contralateral side (p < .001). Talar spur was present in the varus side of all 30 patients on the axial view of weightbearing computed tomography and in the control side of 10 patients. After the simulation of talar tilt correction, talofibular impingement (overlap) occurred in all 30 patients with a larger extent in the severe talar tilt subgroup (p < .001). Conclusion: Talofibular impingement by lateral gutter osteophytes is closely related to increased talar tilt in patients with incongruent varus ankle osteoarthritis. Therefore, lateral gutter osteophytes should be resected to stabilize mortise and improve clinical outcomes.

Correction of the Valgus Ankle with a Joint Sparing Supra-Malleolar Osteotomy: The Modified Wiltse Technique

The valgus ankle is a common cause of pain, deformity, and disability in patients. Addressing these deformities with extraarticular osteotomies is a valuable, joint-sparing treatment option. The modified Wiltse osteotomy provides correction of the mechanical alignment as well as allowing inherent stability. Accurate templating of the Wiltse triangle enables reproducible, accurate intraoperative results.

Joint Preserving Surgery for Valgus Ankle Osteoarthritis

Valgus ankle OA is a complex problem with multiple etiologies that can either be isolated or superimposed on top of other medical or musculoskeletal disorders. Proper medical history, physical, and preoperative radiological examinations are crucial in deciding on surgery and planning the surgical approach. JPS, especially the varisating medial closing-wedge SMOT with solid plate fixation, has been consistently associated with good outcomes for patients with valgus ankle OA. To further improve JPS for valgus ankle OA, further clinical and biomechanical studies are required to address the long-term clinical and functional outcomes and complications.

Analysis of Whole Limb Alignment in Ankle Arthritis

A full-length standing posteroanterior radiograph that includes the calcaneus (hip-to-calcaneus radiograph) is obtained for evaluation of the mechanical axis of the entire lower limb in patients with a lower limb condition involving malalignment. Such evaluation clarifies several pathomechanical aspects of hindfoot disorders, facilitates surgical planning, and elucidates factors contributing to unsatisfactory results of a particular operation. Whole limb alignment is influenced not only by the knee joint but also by the ankle joint; thus, knee realignment influences hindfoot alignment and vice versa. It is essential to analyze alignment of the whole limb in planning corrective lower limb surgery.

Joint Preservation Strategies for Managing Varus Ankle Deformities

Joint preserving strategies have evolved to a successful treatment option in early and midstage medial ankle OA caused by varus deformity. Though talar tilt can often not be fully corrected, it provides substantial postoperative pain relief, functional improvement, and slowing of the degenerative process. Osseous balancing with osteotomies is the main step for restoration of ankle mechanics and normalization of joint load. Overall, the key for success is to understand the underlying causes that have contributed to the varus OA in each case, and to use all treatment modalities necessary to restore appropriate alignment of the hindfoot complex.

The Assessment of Ankle Osteoarthritis with Weight-Bearing Computed Tomography

The standard for diagnostic radiographic imaging in foot and ankle surgery was until 2012 radiographs with full weight-bearing without any useful alternative. Weight-bearing cone-beam computed tomography (WBCT) was introduced 2012 for foot and ankle use as a new technology that allows 3D imaging with full weight-bearing which should be not influenced by projection and/or foot orientation. The assessment of ankle osteoarthritis with WBCT including the description of healthy status, effect of alignment and7or (in)stability is extensively illustrated in this review article.

Joint Preservation Surgery for Varus and Posterior Ankle Arthritis Associated with Flatfoot Deformity

This article introduces novel types of ankle arthritis related to a flatfoot deformity. There has been a long-held belief that severe unmanaged flatfoot deformity leads to valgus ankle arthritis, due to deltoid ligament insufficiency. However, flatfoot deformity can also give rise to varus ankle arthritis as the talus and calcaneus subluxate into opposite directions. Plantarflexion and posterior translation of the talus in the sagittal plane contributes to the eccentric narrowing of the posterior aspect of the tibiotalar joint, which the authors termed posterior ankle arthritis. Subtalar arthrodesis was performed to address the opposing dynamics of the talus and calcaneus, and was combined with a medial longitudinal arch reconstruction in most cases of posterior ankle arthritis and in selected cases of varus ankle arthritis, and satisfactory clinical and radiological results were achieved.

Knee-ankle joint line angle: a significant contributor to high-degree knee joint line obliquity in medial opening wedge high tibial osteotomy

Background

Medial opening wedge high tibial osteotomy (MOWHTO) changes the knee joint inclination in the coronal plane, which can be compensated by the ankle joint. Once there is a decompensated knee joint obliquity, it can induce excessive shear force on the articular cartilage. This study aimed to investigate the capacity of the compensation by analyzing the correlation of the knee-ankle joint line angle (KAJA) and the knee joint line obliquity (KJLO).

Patients and Methods

Ninety-six patients undergoing MOWHTO were included. We measured potential predictors including preoperative or postoperative body mass index (BMI), weight-bearing line (WBL) ratio/correction amount, knee-ankle joint line angle(KAJA), mechanical lateral distal femoral angle (mLDFA), medial proximal tibia angle (MPTA), ankle joint line obliquity (AJLO), mechanical hip-knee-ankle angle (mHKA) and joint line convergence angle (JLCA). The correlations of these predictors and postoperative KJLO were determined using Pearson correlation coefficient. The contribution of significant predictors was further analyzed using multiple linear regression. Finally, the cutoff value of the most contributing factor resulting in decompensated KJLO was derived with receiver operating characteristic (ROC) curve analysis.

Results

Preoperative AJLO, JLCA, MPTA, mHKA and KJLO and postoperative KAJA and MPTA correlated with postoperative KJLO. After multiple linear regression, only preoperative AJLO and JLCA and postoperative KAJA still showed significant contribution to postoperative KJLO. Postoperative KAJA made the greatest contribution. The cutoff value of postoperative KAJA was at 9.6° after ROC analysis. The incidence rate of high-grade KJLO was 69.6% when postoperative KAJA exceeded 9.6°.

Conclusions

Postoperative KAJA is a significant contributor to high-grade KJLO after MOWHTO. The incidence was increased at angles greater than 9.6°. The results suggest that KAJA should be carefully assessed during preoperative planning or intraoperative evaluation. Postoperative KAJA < 9.6° can lower the rate of early high-degree KJLO.

Low tibial valgization osteotomy for varus ankle arthritis - does age effect the outcome?

BACKGROUND

Evidence-based literature identifying the age limit for low tibial valgization osteotomy (LTO) is lacking to date. We addressed the following research questions: (1) is LTO effective for ankle arthritis in patients over 65 years?; (2) does patients' age alter the effectiveness of LTO?; and (3) does preoperative Takakura stage affect the degree of correction in patients over 65 years?

METHODS

We retrospectively reviewed the radiographic and clinical findings of 49 cases which underwent LTO. Patients were divided into two groups according to age at operation (19 cases in group 1 aged ≥65 years and 30 cases in group 2 aged <65). Patients in a single group were regrouped into two subgroups according to preoperative Takakura stage (stage II + IIIA versus IIIB) to determine if the degree of correction varied in Takakura stage IIIB.

RESULTS

Significant changes in radiographic parameters were observed with no significant differences in the amounts of correction between groups 1 and 2. Comparison of Takakura stage II + IIIA in group 1 to that in group 2 and stage IIIB in group 1 to that in group 2 revealed no significant differences in the amounts of correction.

CONCLUSION

LTO could be indicated for patients over 65 years if patient selection was appropriate. LTO in patients over 65 years showed similar radiographic improvements to those in younger patients, and the correction was successfully maintained during the follow-up period. The correctional power of all radiographic parameters did not vary by preoperative Takakura stage.

LEVEL OF EVIDENCE

Level III, comparative series.

Eccentric ankle arthritis in the sagittal plane: a novel description of anterior and posterior ankle arthritis

BACKGROUND

To report radiographic characteristics of anterior and posterior ankle arthritis, which demonstrates the eccentric narrowing of either aspect of the tibiotalar joint in the sagittal plane.

METHODS

Radiographic analysis of 19 ankles with anterior arthritis and 16 ankles with posterior arthritis was performed, which were defined as having both (1) eccentric narrowing of the anterior or posterior tibiotalar joint space on lateral radiographs and (2) talar tilt angle less than 4 degrees on anteroposterior radiographs. Measured radiographic parameters were: Talar tilt angle, medial distal tibial angle (MDTA), talar center migration (TCM), anterior distal tibial angle (ADTA), tibial axis-to-talus ratio (TT ratio), talo-first metatarsal (Meary) angle, hindfoot alignment angle (HAA), hindfoot moment arm, and mechanical axis deviation (MAD). An Intergroup comparison analysis, including a normal control group, was also performed.

RESULTS

The TT ratio was significantly different between each group, indicating a distinct talus position in the sagittal plane. The anterior group had a significantly larger TCM than the control group and lower ADTA compared to other groups, indicating medial translation of the talus and anterior opening of the tibial plafond. The posterior group demonstrated a significantly higher Meary angle and lower HAA compared to other groups and lower MDTA compared to the control group, indicating lower medial longitudinal arch, valgus heel alignment, and varus tibial plafond. The MAD was significantly higher in both the anterior and posterior groups than the control group, indicating varus lower limb alignment.

CONCLUSION

Anterior ankle arthritis demonstrated anteromedial translation of the talus and anterior opening of the tibial plafond. Posterior ankle arthritis was associated with the lower medial longitudinal arch and hindfoot valgus, indicating an association with flatfoot deformity. Both anterior and posterior ankle arthritis were associated with varus lower limb alignment.

Clinical and Radiographic Results of Ankle Joint Preservation Surgery in Posterior Ankle Arthritis

BACKGROUND

Little information is available about how to manage ankles with eccentric arthritis in the sagittal plane. This study aimed to report clinical and radiographic outcomes following joint preservation surgery for ankles with eccentric arthritis at the posterior tibiotalar joint and a plantarflexed talus in the sagittal plane, which we named posterior ankle arthritis.

METHODS

Ten ankles with posterior ankle arthritis were treated with realignment surgery between 2017 and 2018. Posterior ankle arthritis was defined as having both (1) eccentric narrowing of the joint space at the posterior aspect of the tibiotalar joint on weightbearing lateral radiographs and (2) coronal talar tilt angle less than 4 degrees on weightbearing anteroposterior radiographs. Flatfoot reconstruction with a hindfoot arthrodesis procedure was performed in all patients (subtalar arthrodesis, n = 9; triple arthrodesis, n = 1), and a supramalleolar osteotomy was added in patients with varus distal tibial alignment (n = 6). Pain, functional outcome (foot function index [FFI]), radiographic arthritis stage (stage I to IV), and 9 radiographic parameters, including lateral talar center migration (LTCM), were evaluated on pre- and postoperative weightbearing radiographs. All patients completed a minimum 2-year follow-up.

RESULTS

Preoperative radiographic evaluation demonstrated that ankles with posterior arthritis had a lower medial longitudinal arch, forefoot abduction, and valgus hindfoot alignment. Postoperatively, sagittal tibiotalar alignment was restored, as evidenced by an improved median LTCM from -3.3 to -0.3 mm (P < .001). The radiographic arthritis stage improved in 7 (70%) patients, whereas 3 (30%) remain unchanged in the same stage. The median score for pain (visual analog scale) decreased significantly from 8 to 2, and the median FFI improved significantly from 67.8 to 23.4 (P < .001). None of the patients underwent conversion to joint-sacrificing procedures at the latest follow-up.

CONCLUSION

The study results suggest a possible relationship between posterior ankle arthritis and the plantarflexion of the talus, which can be seen in the setting of a flatfoot deformity. Reconstruction of the flatfoot deformity using subtalar arthrodesis restored the tibiotalar relationship in the sagittal plane and resulted in clinical improvements at an average 2.3-year follow-up in this 10-ankle case series.

LEVEL OF EVIDENCE

Level IV, case series.

Fibular osteotomy is helpful for talar reduction in the treatment of varus ankle osteoarthritis with supramalleolar osteotomy

BACKGROUND

There have been debates on the necessity of fibular osteotomy (FO) in supramalleolar osteotomy (SMOT) for the treatment of varus ankle osteoarthritis. The purpose of the current study was to compare the clinical and radiological outcomes between SMOT with and without FO in the treatment of varus ankle osteoarthritis.

METHODS

The SMOT group included 39 patients, and the SMOT with FO group included 24 patients. The basic information reached no significant difference between groups. The American Orthopedic Foot and Ankle Society (AOFAS) ankle-hindfoot score, Ankle Osteoarthritis Scale (AOS), modified Takakura stage and range of motion (ROM) were used for the functional evaluation. The radiologic parameters were assessed at the last follow-up to compare the degree of talar reduction between the two groups.

RESULTS

Both groups achieved significant improvements in AOFAS scores, modified Takakura stage, as well as AOS pain and functional scores (P < 0.001). The ROM of the ankle joint in the SMOT group was significantly decreased (P = 0.022). In both groups, all of the radiological parameters were significantly improved (P < 0.01). The tibiofibular clear space (TFCS) was significantly widened in the SMOT group (P < 0.001). No significant difference was found between the two groups according to the functional outcomes. However, the talar tilt angle (TT) and hindfoot alignment angle (HFA) in the SMOT with FO group were significantly smaller than those in the SMOT group (P < 0.05). The TFCS was significantly widened in the SMOT group (P = 0.001). The medial displacement of the talus (MDT) was better reduced in the SMOT with FO group (P = 0.006).

CONCLUSION

SMOT is a promising procedure for functional improvement and malalignment correction in varus ankle osteoarthritis but reduces ankle range of motion. If SMOT is combined with FO, talar tilt and medial displacement will be better reduced.

A comparative biomechanical study of the Distal Tibia Nail against compression plating for the osteosynthesis of supramalleolar corrective osteotomies

The Distal Tibia Nail (DTN; Mizuho, Japan) has demonstrated higher biomechanical stiffness to locking plates in previous research for A3 distal tibia fractures. It is here investigated as a fixation option for supramalleolar corrective osteotomies (SMOT). Sixteen Sawbones tibiae were implanted with either a DTN (n = 8) or Medial Distal Tibia Plate (MDTP; n = 8) and a SMOT simulated. Two surgical outcome scenarios were envisaged: "best-case" representing an intact lateral cortex, and "worst-case" representing a fractured lateral cortex. All samples were subjected to compressive (350 N, 700 N) and torsional (± 4 Nm, ± 8 Nm) testing. Samples were evaluated using calculated construct stiffness from force-displacement data, interfragmentary movement and Von Mises' strain distribution. The DTN demonstrated a greater compressive stiffness for the best-case surgical scenario, whereas the MDTP showed higher stiffness (p < 0.05) for the worst-case surgical scenario. In torsional testing, the DTN proved more resistant to torsion in the worst-case surgical setup (p < 0.05) for both ± 4 Nm and ± 8 Nm. The equivalent stiffness of the DTN against the MDTP supports the use of this implant for SMOT fixation and should be considered as a treatment option particularly in patients presenting vascularisation problems where the MDTP is an inappropriate choice.

Clinical Outcome of Kissing Mosaicplasty for Treatment of Asymmetric Medial Tibiotalar Osteoarthritis: A Case Report

CASE

We report a case of asymmetric medial ankle arthritis that was treated by medial malleolar osteotomy and oblique fibular osteotomy to expose and resurface both the medial talar dome and medial tibial plafond articular surfaces.

CONCLUSION

This technique permitted a unique application of mosaicplasty in which osteochondral plugs were placed in a "kissing" orientation. The outcome seen here suggests the possibility of mosaicplasty as a viable option for treatment of localized ankle arthritis. In addition, this exposure technique is also applicable to treating isolated lesions of the medial tibial plateau.

Using the Lower Limb Adduction Angle to Predict Postoperative Knee Joint-Line Obliquity After Open-Wedge High Tibial Osteotomy

Background:

Knee joint-line orientation is altered after open-wedge high tibial osteotomy (OWHTO), and excessive joint-line obliquity (JLO) can adversely affect outcomes. Little is known regarding preoperative prediction of postoperative knee JLO.

Purpose/Hypothesis:

The purpose of this study was to assess the correlation between the amount of lower limb adduction and changes in knee JLO after OWHTO. The hypothesis was that postoperative knee JLO could be predicted using the amount of lower limb adduction after OWHTO.

Study Design:

Case series; Level of evidence, 4.

Methods:

The records of 67 patients (77 knees) who underwent OWHTO for medial compartment osteoarthritis were retrospectively reviewed. The mechanical hip-knee-ankle (HKA) axis, lateral distal femoral angle, medial proximal tibial angle (MPTA), knee JLO, ankle JLO, and joint-line convergence angle were measured on standing whole-leg plain radiographs preoperatively and at 1 year postoperatively. The limb adduction angle was defined as the angle between the native weightbearing line (WBL) and the planned WBL on preoperative standing whole-leg plain radiographs. The predicted knee JLO was calculated as the sum of the preoperative knee JLO and the limb adduction angle. Multivariable linear regression analysis was used to identify the preoperative radiologic factors associated with the postoperative knee JLO. The agreement between postoperative and predicted values was determined using intraclass correlation coefficients (ICCs).

Results:

The estimated limb adduction angle was 4.2° ± 1.3°, and the predicted knee JLO was 4.9° ± 3.0°. The actual postoperative knee JLO was 4.5° ± 2.4°, which was a significant increase from 0.7° ± 2.4° preoperatively (P < .001). Excellent agreement was found between the predicted knee JLO and postoperative knee JLO (ICC = 0.928; P < .001). Limb adduction angle and changes in preoperative MPTA were significantly associated with changes in knee JLO (P < .001). On multivariable linear regression analysis, preoperative knee JLO and limb adduction angle were significantly associated with postoperative knee JLO (P < .001; R² = 0.83).

Conclusion:

Changes in knee JLO after OWHTO were associated with adduction of the lower limb after OWHTO. During preoperative planning, postoperative knee JLO can be predicted as the sum of the preoperative knee JLO and the limb adduction angle between the preoperative WBL and planned WBL.

Radiographic differences in the concomitant deformities in two types of medial ankle osteoarthritis

Objectives

Motion preserving surgeries could be unsuccessful because of underestimation of deformities of the foot and knee in ankle osteoarthritis. This study aimed to investigate the concomitant deformities in medial ankle osteoarthritis and the difference between the two types, varus angulation and medial translation.

Methods

A retrospective study was conducted using medical records and radiographic data. Patients with medial ankle osteoarthritis that underwent weight-bearing X ray imaging and radiographic measurements including tibial plafond inclination (TPI), tibiotalar tilt angle (TT), lateral talo-first metatarsal angle, naviculo-cuboid overlap, and mechanical tibiofemoral angle (mTFA) were studied. The patients were categorized into two groups, the varus angulation group (TT ≥4°) and medial translation group (TT <4°). The radiographic measurements were compared between the two groups.

Results

A total of 102 patients (male = 44; female = 58) were included; the mean age was 64.9 years (SD 8.3 years). The varus rotation group (N = 66) showed a significantly smaller lateral talo-first metatarsal angle (p<0.001), naviculo-cuboid overlap (p<0.001), and mTFA (p = 0.019) compared to the medial displacement group (N = 36). The TT showed a significant correlation with lateral talo-first metatarsal angle (r = -0.520, p<0.001), naviculo-cuboid overlap (r = -0.501, p<0.001), and mTFA (r = -0.243, p = 0.014). Lateral talo-first metatarsal angle was found to be the significant factor (p = 0.018) discriminating varus angulation and medial translation types in the binary logistic analysis.

Conclusions

Varus angulation of the ankle was correlated with knee alignment and foot deformity. Radiographic indices were different between the varus angulation and medial translation groups. The role of concomitant deformities needs to be further investigated in terms of a causal relationship. Surgeons need to pay attention to concomitant deformities in the treatment of medial ankle osteoarthritis.

Anterior distal tibial plafond-plasty for the treatment of posttraumatic ankle osteoarthritis with anterior translation of the talus

Posttraumatic ankle osteoarthritis (OA) represents a significant challenge to orthopedic surgeons, especially in cases of anterior talar translation and concomitant impaction of the anterior distal tibial plafond. The aim of this study was to evaluate the clinical outcomes of an intra-articular osteotomy for the management of these patients. A total of 21 patients meeting our criteria were retrospectively reviewed. Sixteen patients sustained initial pilon fractures, while five patients had Weber type C ankle fractures. Anterior distal tibial plafond-plasty was performed to address the impaction and anterior translation of the talus. The American Orthopedic Foot and Ankle Society (AOFAS) hindfoot score and visual analog scale (VAS) score were utilized as clinical outcomes. The lateral talar station (LTS), tibial lateral surface (TLS) angle, tibial anterior surface angle and talocrural angle were evaluated pre- and postoperatively. The modified Kellgren-Lawrence score was used for the evaluation of sagittal ankle OA. The average age at surgery was 35 years, and the average follow-up duration was 34 months. The AOFAS hindfoot score increased from 26 to 71 (p < 0.01), and the VAS score improved from 7 to 2 (p < 0.01). The LTS improved from 9.0 to 2.3 mm (p < 0.01), and the TLS angle improved from 72° to 81° (p < 0.01). Of the 21 patients, 18 showed improvement in or no worsening of ankle OA on the sagittal plane, while 3 developed advanced ankle OA. A congruent ankle joint on the sagittal plane could be achieved by anterior distal tibial plafond-plasty. This is a valuable treatment option for the salvage of posttraumatic ankle OA with anterior translation of the talus.

Perioperative axial loading computed tomography findings in varus ankle osteoarthritis: Effect of supramalleolar osteotomy on abnormal internal rotation of the talus

BACKGROUND

We used axial loading computed tomography (AL CT) to evaluate preoperative and postoperative talocrural joints of patients who underwent supramalleolar osteotomy (SMO) to treat varus ankle osteoarthritis.

METHODS

We performed retrospective analyses of 16 patients (18 feet) who underwent SMO including fibular osteotomy. Radiographic assessment was performed with weightbearing radiographs and AL CT. Clinical outcomes were assessed based on American Orthopedic Foot & Ankle Society (AOFAS) scale, visual analog scale (VAS) for pain, and Foot and Ankle Ability Measure (FAAM).

RESULTS

The mean 2-year follow-up tibial-ankle surface angle, talar tilt angle, Takakura stage, and tibial-lateral surface angle were all significantly different relative to preoperative parameters (P<.05). The mean 6-month follow-up talus rotation ratio was significantly corrected compared to the preoperative value (P=.001). The mean 2-year follow-up AOFAS, VAS at gait, and FAAM scores were all significantly improved relative to preoperative measurements (P=.001).

CONCLUSIONS

Abnormal internal rotation of the talus in mild to moderate varus ankle osteoarthritis found on AL CT was significantly corrected after SMO.

LEVEL OF EVIDENCE

Therapeutic Level IV.

The 50 most cited articles in ankle surgery

This paper aims to establish a ranking of the 50 most cited research articles pertaining to ankle surgery in the field of orthopaedics. In addition, the demographic features such as the date of publications, location of primary author and country of the publisher were all analysed. Studies similar to these have been completed in other subspecialties, however we were not able to find studies relevant to ankle surgery. The Web of Science Cor Collection Database was utilised to identify the target articles. The most cited article was cited 394 times and the least was cited 120 times, and the majority of articles were published in the United States of America. This research will benefit the scientific community in identifying popular research topics, identifying lacking fields and identifying key hubs in the field of ankle surgery.

Aggravation of Ankle Varus Incongruency Following Total Knee Replacement Correcting ≥10° of Genu Varum Deformity: A Radiographic Assessment

BACKGROUND

This study aimed to investigate the change in ankle varus incongruencies following total knee replacement (TKR) in patients with preoperative genu varum deformity of ≥10°.

METHODS

The study cohort was composed of patients who underwent TKR in a single institution for knee osteoarthritis with preoperative genu varum deformity of ≥10° and concomitant varus ankle incongruencies. Eight radiographic measurements were evaluated preoperatively and postoperatively: mechanical tibiofemoral angle, mechanical lateral distal femoral angle, medial proximal tibial angle, lateral distal tibial angle, tibial plafond inclination, talar inclination, tibiotalar tilt angle (TTTA), and tibia-mechanical axis angle. Of these, TTTA represented the quantitative degree of ankle joint incongruency.

RESULTS

A total of 110 patients (male = 2; female = 108) were included in the analysis. The mean patient age was 68.9 (standard deviation [SD] 7.2) years at the time of TKR. All radiographic measurements showed significant changes postoperatively, representing the appropriate correction of genu varum deformity and restoration of the mechanical axis. Nineteen patients (17.3%) showed postoperative decrease in TTTA, 2 (1.8%) remained the same, and 89 (80.9%) showed increase. Overall, mean preoperative and postoperative TTTA were 3.3° (SD 2.2°) and 4.7° (SD 2.9°), respectively (P < .001), representing the aggravation of varus ankle incongruencies.

CONCLUSION

Varus ankle incongruencies showed aggravation following TKR despite correction of genu varum deformity and restoration of the mechanical axis. This could be an important cause of postoperative increase or development of ankle pain following TKR. Therefore, patients with preoperative varus ankle incongruencies need to be warned of possible aggravation of ankle symptoms and be evaluated before TKR.

LEVEL OF EVIDENCE

Prognostic level III.

Low Tibial Valgization Osteotomy for More Severe Varus Ankle Arthritis

BACKGROUND

Low tibial valgization osteotomy with medial opening wedge (LTO) is generally indicated for ankle arthritis with a small talar tilt (TT). We addressed the following research questions: the efficacy of LTO for more significant varus ankle arthritis, the effect of additional inframalleolar correction followed by LTO, and the preoperative or operation-related factors influencing postoperative TT decrease.

METHODS

We retrospectively reviewed the radiographic and clinical findings of 31 patients with more significant varus ankle arthritis (≥8 degrees) who underwent LTO or LTO plus inframalleolar correction. We grouped the included patients according to combination with inframalleolar correction and postoperative decreased TT. Furthermore, a binary logistic regression analysis was performed to determine the factors influencing postoperative TT decrease.

RESULTS

Even though the mean TT was unchanged postoperatively (from 12.1 to 9.9 degrees, P = .052), clinical parameters were significantly increased. In the group with concomitant inframalleolar correction, we found that TT was more corrected (3.9 vs 1.8 degrees, P = .023) with a greater lateralization of the talar center and a greater correction of the hindfoot alignment to valgus. The results of the binary logistic regression analysis showed a significant relationship between postoperative decreased TT and preoperative talar center migration (P = .016), hindfoot alignment angle (P = .033), hindfoot moment arm (P = .041), and hindfoot alignment ratio (P = .016).

CONCLUSION

LTO in more significant varus ankle arthritis could result in clinical improvement, although TT was not significantly changed. We recommend adding inframalleolar correction after LTO for the patients with more significant varus ankle arthritis.

LEVEL OF EVIDENCE

Level III, comparative series.

Supramalleolar Distal Tibiofibular Osteotomy for Medial Ankle Osteoarthritis: Current Concepts

The supramalleolar osteotomy is a joint-preserving surgical procedure. It is a very good treatment option for the asymmetric varus ankle and medial compartment osteoarthritis. The primary objective of the procedure is to shift medial concentration of stress toward the lateral intact articular cartilage to redistribute the joint loads during ambulation. Several studies have shown that deformities of the ankle result in uneven load distribution in the ankle joint, which eventually leads to articular cartilage degeneration. Since the lateral articular cartilage is intact, joint-sacrificing procedures such as total ankle replacement or ankle arthrodesis are not the most appropriate treatment choices for medial compartment arthritis. Results of supramalleolar osteotomies are very promising in terms of functional outcome and pain relief. In younger patients with medial compartment varus ankle osteoarthritis or even with a normal tibial anterior surface angle, supramalleolar osteotomies can be performed to realign the ankle to promote regeneration of the asymmetrically damaged cartilage. In this review article, we will discuss the indications, complications, surgical techniques, and outcomes of the supramalleolar osteotomy reported in the current literature.

Change in gait biomechanics after total ankle replacement and ankle arthrodesis: a systematic review and meta-analysis

BACKGROUND

The aim of this systematic review with meta-analysis was to determine the change in gait biomechanics after total ankle replacement and ankle arthrodesis for end-stage osteoarthritis.

METHODS

Electronic databases were searched up until May 2019. Peer-reviewed journal studies including adult participants suffering from end-stage ankle osteoarthritis and reporting pre- and post-operative kinematics, kinetics and spatio-temporal effects of total ankle replacement and ankle arthrodesis during walking were included with a minimum of 12 months follow-up. Seventeen suitable studies were identified and assessed according to methodological and biomechanical qualities. Meta-analysis was performed by calculating the effect size using standard mean differences between pre- and post-operative gait status.

FINDINGS

Seventeen studies with a total of 883 patients were included. Meta-analysis revealed moderate evidence of an improvement in lower limb kinematics, kinetics and spatio-temporal parameters after total ankle replacement. Moderate evidence indicated an increase in ankle moment, hip range of motion and walking speed after ankle arthrodesis.

INTERPRETATION

The currently available evidence base of research papers evaluating changes in gait biomechanics after total ankle replacement and ankle arthrodesis is limited by a lack of prospective research, low sample sizes and heterogeneity in the patho-etiology of ankle osteoarthritis. Following total ankle replacement, improvements were demonstrated for spatio-temporal, kinematic and kinetic gait patterns compared to the pre-operative measures. Improvements in gait mechanics after ankle arthrodesis were limited to walking speed and ankle moment. Increased hip range of motion after ankle arthrodesis could represent a sign of compensation for the lack of ankle motion.

Is Lower-limb Alignment Associated with Hindfoot Deformity in the Coronal Plane? A Weightbearing CT Analysis

BACKGROUND

The goals of lower limb reconstruction are to restore alignment, to improve function, and to reduce pain. However, it remains unclear whether alignment of the lower limb and hindfoot are associated because an accurate assessment of hindfoot deformities has been limited by superposition on plain radiography. Consequently, surgeons often overlook hindfoot deformity when planning orthopaedic procedures of the lower limb. Therefore, we used weight-bearing CT to quantify hindfoot deformity related to lower limb alignment in the coronal plane.

QUESTIONS/PURPOSES

(1) Is lower-limb alignment different in varus than in valgus hindfoot deformities for patients with and without tibiotalar joint osteoarthritis? (2) Does a hindfoot deformity correlate with lower-limb alignment in patients with and without tibiotalar joint osteoarthritis? (3) Is joint line orientation different in varus than in valgus hindfoot deformities for patients with tibiotalar joint osteoarthritis? (4) Does a hindfoot deformity correlate with joint line orientation in patients with tibiotalar joint osteoarthritis?

METHODS

Between January 2015 and December 2017, one foot and ankle surgeon obtained weightbearing CT scans as second-line imaging for 184 patients with ankle and hindfoot disorders. In 69% (127 of 184 patients) of this cohort, a combined weightbearing CT and full-leg radiograph was performed when symptomatic hindfoot deformities were present. Of those, 85% (109 of 127 patients) with a median (range) age of 53 years (23 to 75) were confirmed eligible based on the inclusion and exclusion criteria of this retrospective comparative study. The Takakura classification was used to divide the cohort into patients with (n = 74) and without (n = 35) osteoarthritis of the tibiotalar joint. Lower-limb measurements, obtained from the full-leg radiographs, consisted of the mechanical tibiofemoral angle, mechanical tibia angle, and proximal tibial joint line angle. Weightbearing CT images were used to determine the hindfoot's alignment (mechanical hindfoot angle), the tibiotalar joint alignment (distal tibial joint line angle and talar tilt angle) and the subtalar joint alignment (subtalar vertical angle). These values were statistically assessed with an ANOVA and a pairwise comparison was subsequently performed with Tukey's adjustment. A linear regression analysis was performed using the Pearson correlation coefficient (r). A reliability analysis was performed using the intraclass correlation coefficient.

RESULTS

Lower limb alignment differed among patients with hindfoot deformity and among patients with or without tibiotalar joint osteoarthritis. In patients with tibiotalar joint osteoarthritis, we found knee valgus in presence of hindfoot varus deformity and knee varus in presence of hindfoot valgus deformity (mechanical tibiofemoral angle 0.3 ± 2.6° versus -1.8 ± 2.1°; p < 0.001; mechanical tibia angle -1.4 ± 2.2° versus -4.3 ± 1.9°; p < 0.001). Patients without tibiotalar joint osteoarthritis demonstrated knee varus in the presence of hindfoot varus deformity compared with knee valgus in presence of hindfoot valgus deformity (mechanical tibiofemoral angle -2.2 ± 2.2° versus 0.9 ± 2.4°; p < 0.001; mechanical tibia angle -1.8 ± 2.1° versus -4.3 ± 1.9°; p < 0.001). Patients with more valgus deformity in the hindfoot tended to have more tibiofemoral varus (r = -0.38) and tibial varus (r = -0.53), when tibiotalar joint osteoarthritis was present (p < 0.001). Conversely, patients with more valgus deformity in the hindfoot tended to have more tibiofemoral valgus (r = 0.4) and tibial valgus (r = 0.46), when tibiotalar joint osteoarthritis was absent (p < 0.001). The proximal joint line of the tibia had greater varus orientation in patients with a hindfoot valgus deformity compared with greater valgus orientation in patients with a hindfoot varus deformity (proximal tibial joint line angle 88.5 ± 2.0° versus 90.6 ± 2.2°; p < 0.05). Patients with more valgus deformity in the hindfoot tended to have more varus angulation of the proximal tibial joint line angle (r = 0.31; p < 0.05).

CONCLUSIONS

In patients with osteoarthritis of the tibiotalar joint, varus angulation of the knee was associated with hindfoot valgus deformity and valgus angulation of the knee was associated with hindfoot varus deformity. Patients without tibiotalar joint osteoarthritis exhibited the same deviation at the level of the knee and hindfoot. These distinct radiographic findings were most pronounced in the alignment of the tibia relative to the hindfoot deformity. This suggests a detailed examination of hindfoot alignment before knee deformity correction at the level of the proximal tibia, to avoid postoperative increase of pre-existing hindfoot deformity. Other differences detected between the radiographic parameters were less pronounced and varied within the subgroups. Future research could identify prospectively which of these parameters contain clinical relevance by progressing osteoarthritis or deformity and how they can be altered by corrective treatment.

LEVEL OF EVIDENCE

Level III, prognostic study.

Supramalleolar osteotomy combined with lateral ligament reconstruction and talofibular immobilization for varus ankle osteoarthritis with excessive talar tilt angle

Background

Although supramalleolar osteotomy is the main joint-preserving method for the treatment of varus ankle osteoarthritis, it tends to be ineffective when ankle osteoarthritis presents in combination with an excessive talar tilt angle. The purpose of this study was to present a new surgical technique, supramalleolar osteotomy combined with lateral ligament reconstruction and talofibular immobilization, for the treatment of varus ankle osteoarthritis with an excessive talus tilt angle and to evaluate the clinical and radiological results.

Methods

From January 2013 to October 2016, a total of 17 patients with 17 cases of varus ankle arthritis with excessive talar tilt angles (larger than 7.3°) underwent surgical treatment using our new technique. The American Orthopaedic Foot and Ankle Society (AOFAS) clinical ankle-hindfoot scale and a visual analogue scale (VAS) were used to evaluate ankle function and pain before surgery and at the last follow-up. The medial distal tibial angle (MDTA), anterior distal tibial angle (ADTA), talar tilt angle (TTA), and hindfoot moment arm values (HMAVs) were evaluated on weight-bearing radiographs acquired preoperatively and at the last follow-up.

Results

The AOFAS score improved significantly from 45.8 ± 2.1 before surgery to 84.8 ± 1.8 after surgery (p < 0.001), and the VAS score decreased from 4.9 ± 0.4 to 1.1 ± 0.2 (p < 0.001). The MDTA, TTA, and HMAV changed from 80.9° ± 0.4° to 90.1° ± 0.4°, 11.7° ± 0.6° to 1.4° ± 0.3°, and 12.6 mm ± 0.8 mm to 4.2 mm ± 0.6 mm, respectively (each p < 0.001). The ADTA showed no obvious change (p = 0.370). The staging of 11 cases (65%) improved. Intramuscular vein thrombosis of the lower limbs occurred in 1 patient 1 week after surgery, and superficial infection occurred in 1 patient.

Conclusions

Supramalleolar osteotomy combined with lateral ligament reconstruction and talofibular immobilization can correct the load of the weight-bearing ankle and effectively improve the ankle function. As the talar tilt angle can be significantly improved after surgery, this technique can be used for the treatment of varus ankle osteoarthritis with an excessive TTA.

[Correction of posttraumatic deformities of the distal tibia with focal dome osteotomy]

BACKGROUND

Supramalleolar deformities require surgical correction to avoid posttraumatic osteoarthrosis of the knee or ankle joint and to prevent definitive treatment options, such as total ankle arthroplasty or arthrodesis of the ankle joint. Various methods for the operative correction of supramalleolar deformities have been described in the literature.

OBJECTIVE

What results can be achieved with focal dome osteotomy to correct posttraumatic supramalleolar deformities?

MATERIAL AND METHODS

A total of 10 patients (mean age 37 years) with a supramalleolar posttraumatic deformity were treated by focal dome osteotomy. The mean follow-up was 27 months (min. 6, max. 105 months), 5 patients were female and 5 male. The supramalleolar varus/valgus deformity was on average 20° (at least 12°, maximum 33°). Preoperative and postoperative mechanical axis and joint angles were determined on digital radiographs. The American Orthopedic Foot and Ankle Society (AOFAS) score was used to assess the clinical outcome.

RESULTS

In seven patients the anatomical leg axis could be restored. In three patients a residual deformity of 2.8° was observed. Bone grafting was not necessary in any of the cases. Of the patients eight had free ankle mobility and two showed an average movement limit of 30° compared to the contralateral side. Posttraumatic ankle arthrosis was not observed in the short-term and medium-term results. The mean AOFAS score of 80 points (minimum 70, maximum 98) documented a functionally good result.

CONCLUSION

Supramalleolar dome type osteotomy is a technically difficult method for acute correction of supramalleolar deformities. The functional results and complication rates are comparable to those in the literature for alternative osteotomy techniques.