Cost-Utility Analysis of Total Ankle Replacement Compared with Ankle Arthrodesis for Patients Aged 50-85 Years with End-Stage Ankle Osteoarthritis: The TARVA Study.

BACKGROUND: Patients with end-stage ankle osteoarthritis suffer from reduced mobility and quality of life and the main surgical treatments are total ankle replacement (TAR) and ankle fusion (AF). OBJECTIVES: Our aim was to calculate the mean incremental cost per quality-adjusted life-year (QALY) of TAR compared with AF in patients with end-stage ankle osteoarthritis, over 52 weeks and over the patients' lifetime. METHOD: We conducted a cost-utility analysis of 282 participants from 17 UK centres recruited to a randomised controlled trial (TARVA). QALYs were calculated using index values from EQ-5D-5L. Resource use information was collected from case report forms and self-completed questionnaires. Primary analysis was within-trial analysis from the National Health Service (NHS) and Personal Social Services (PSS) perspective, while secondary analyses were within-trial analysis from wider perspective and long-term economic modelling. Adjustments were made for baseline resource use and index values. RESULTS: Total cost at 52 weeks was higher in the TAR group compared with the AF group, from the NHS and PSS perspective (mean adjusted difference £2539, 95% confidence interval [CI] £1142, £3897). The difference became very small from the wider perspective (£155, 95% CI -  £1947, £2331). There was no significant difference between TAR and AF in terms of QALYs (mean adjusted difference 0.02, 95% CI -  0.015, 0.05) at 52 weeks post-operation. The incremental cost-effectiveness ratio (ICER) was £131,999 per QALY gained 52 weeks post-operation. Long-term economic modelling resulted in an ICER of £4200 per QALY gained, and there is a 69% probability of TAR being cost effective at a cost-effectiveness threshold of £20,000 per QALY gained. CONCLUSION: TAR does not appear to be cost effective over AF 52 weeks post-operation. A decision model suggests that TAR can be cost effective over the patients' lifetime but there is a need for longer-term prospectively collected data. Clinical trial registration ISRCTN60672307 and ClinicalTrials.gov NCT02128555.

Association of Fusion of the First Metatarsophalangeal Joint and Pes Planus Deformity Correction.

BACKGROUND: There has been scant investigation on the relationship between the distal aspect of the medial longitudinal arch and pes planus deformity. The aim of this study was to investigate whether the reduction and stabilization of the distal aspect of the medial longitudinal arch through fusion of the first metatarsophalangeal joint (MTPJ) can subsequently improve pes planus deformity parameters. This could be useful in both further understanding the role of the distal medial longitudinal arch in patients with pes planus and planning operative intervention in patients with multifactorial medial longitudinal arch problems. METHODS: A retrospective cohort study was undertaken between January 2011 and October 2021, including patients undergoing first MTPJ fusion with a pes planus deformity on weightbearing preoperative radiographs. These were compared to postoperative images, and multiple pes planus measurements were taken for comparison. RESULTS: A total of 511 operations were identified for further analysis, with 48 feet meeting the inclusion criteria. There was a statistically significant reduction identified between the pre- and postoperative measurements of Meary angle (3.75 degrees, 95% CI 2.9-6.47 degrees) and talonavicular coverage angle (1.48 degrees, 95% CI 1.09-3.44 degrees). There was a statistically significant increase between the pre- and postoperative measurements of calcaneal pitch angle (2.32 degrees, 95% CI 0.24-4.41 degrees) and medial cuneiform height (1.25 mm, 95% CI 0.6-1.92 mm). Reduced intermetatarsal angle was significantly associated with an increase in first MTPJ angle postfusion. Many of the measurements made were found "almost perfectly" reproducible by the Landis and Koch description. CONCLUSION: Our results demonstrate that fusion of the first MTPJ is associated with improvement of medial longitudinal arch parameters of a pes planus deformity but not to levels considered to be clinically normal. Therefore, the distal aspect of the medial longitudinal arch could, to some degree, be a feature in the pes planus deformity etiology. LEVEL OF EVIDENCE: Level III, retrospective case control study.

Total Ankle Replacement Versus Arthrodesis for End-Stage Ankle Osteoarthritis: A Randomized Controlled Trial.

BACKGROUND: End-stage ankle osteoarthritis causes severe pain and disability. There are no randomized trials comparing the 2 main surgical treatments: total ankle replacement (TAR) and ankle fusion (AF). OBJECTIVE: To determine which treatment is superior in terms of clinical scores and adverse events. DESIGN: A multicenter, parallel-group, open-label randomized trial. (ISRCTN registry number: 60672307). SETTING: 17 National Health Service trusts across the United Kingdom. PATIENTS: Patients with end-stage ankle osteoarthritis, aged 50 to 85 years, and suitable for either procedure. INTERVENTION: Patients were randomly assigned to TAR or AF surgical treatment. MEASUREMENTS: The primary outcome was change in Manchester-Oxford Foot Questionnaire walking/standing (MOXFQ-W/S) domain scores between baseline and 52 weeks after surgery. No blinding was possible. RESULTS: Between 6 March 2015 and 10 January 2019, a total of 303 patients were randomly assigned; mean age was 68 years, and 71% were men. Twenty-one patients withdrew before surgery, and 281 clinical scores were analyzed. At 52 weeks, the mean MOXFQ-W/S scores improved for both groups. The adjusted difference in the change in MOXFQ-W/S scores from baseline was -5.6 (95% CI, -12.5 to 1.4), showing that TAR improved more than AF, but the difference was not considered clinically or statistically significant. The number of adverse events was similar between groups (109 vs. 104), but there were more wound healing issues in the TAR group and more thromboembolic events and nonunion in the AF group. The symptomatic nonunion rate for AF was 7%. A post hoc analysis suggested superiority of fixed-bearing TAR over AF (-11.1 [CI, -19.3 to -2.9]). LIMITATION: Only 52-week data; pragmatic design creates heterogeneity of implants and surgical techniques. CONCLUSION: Both TAR and AF improve MOXFQ-W/S and had similar clinical scores and number of harms. Total ankle replacement had greater wound healing complications and nerve injuries, whereas AF had greater thromboembolism and nonunion, with a symptomatic nonunion rate of 7%. PRIMARY FUNDING SOURCE: National Institute for Health and Care Research Heath Technology Assessment Programme.

Hallux Valgus Interphalangeus Measurement: Comparison of the 2 Radiographic Methods.

BACKGROUND: To determine the reliability of Delta PP (difference in medial and lateral proximal phalanx wall length) compared with HIA (hallux interphalangeal angle) in the assessment of HVI (hallux valgus interphalangeus) in both preoperative and postoperative radiographs. METHODS: This was a retrospective observational study of 186 feet with hallux valgus. The number of cases required to adequately power the study was 128. Preoperative and postoperative hallux alignment were evaluated by 2 different radiological parameters, Delta PP and HIA. Interobserver variability was assessed independently by 2 authors and compared using a intraclass correlation coefficient. RESULTS: The intraclass correlation coefficient was more than 0.8 for all parameters, thus both HIA and Delta PP measurement provide reliable and reproducible data. Mean HIA significantly increased following surgical correction of hallux valgus. In comparison, the mean Delta PP decreased after correction. This postoperative increase in HIA indicates that preoperative HIA underestimates the magnitude of HVI and therefore is an inaccurate tool for measuring HVI's contribution to the TVDH (total valgus deformity of the hallux) and to preoperative planning. However, the Delta PP was a greater determinant of the phalanx deformity's contribution to the TVDH. CONCLUSION: The outcome of our study shows that both HIA and Delta PP are reproducible when assessing the HVI deformity; however, Delta PP quantifies the amount of correction obtained more precisely. The additional benefit of measuring the Delta PP is that it allows for accurate planning in determining the dimensions of the medial-based wedge of the Akin osteotomy that needs to be resected. LEVELS OF EVIDENCE: Level 4.

Risk Factors for Nonunion After First Metatarsophalangeal Joint Arthrodesis With a Dorsal Locking Plate and Compression Screw Construct: Correction of Hallux Valgus Is Key.

First metatarsophalangeal joint (MTPJ) arthrodesis is currently the gold standard technique for advanced hallux rigidus. This retrospective study aimed to identify the risk factors for nonunion after first MTPJ arthrodesis with a dorsal locking plate and compression screw construct. Between April 2014 and April 2019, 165 consecutive patients (28 men and 137 women; mean age, 60 (range, 28-84) years) who underwent 178 primary first MTPJ arthrodeses were retrospectively reviewed. All arthrodeses were performed using either a dorsal locking plate with an integrated compression screw (Anchorage CP plate, Stryker, n = 97) or a dorsal locking plate (Anchorage V2 plate, Stryker, n = 81) with a separate compression screw (4 mm cannulated ACE screw). Union was defined as bone bridging across the fusion site on at least 2 of the 3 standard foot radiographs (anteroposterior, lateral, oblique) and no MTPJ movement or pain during clinical examination. Potential risk factors for nonunion were analyzed with the use of univariate and multivariate analyses. The overall nonunion rate was 6.2% (11 of 178 cases). The risk factors identified in the univariate analysis included preoperative hallux valgus deformity, postoperative residual hallux valgus deformity, and diabetes (p < .05). Multivariate analysis confirmed that postoperative residual hallux valgus deformity (odds ratio 6.5; p= .015) and diabetes (odds ratio 7.4; p = .019) are independent risk factors for nonunion after first MTPJ arthrodesis. Diabetes is the most important independent risk factor for nonunion after first MTPJ arthrodesis with a dorsal locking plate and compression screw construct. A residual postoperative hallux valgus deformity is associated with a significantly increased risk for nonunion. It is therefore crucial to correct the hallux valgus deformity to a hallux valgus angle of less than 20°.

The anatomy of the anterior inferior tibiofibular ligament and its relationship with the Wagstaffe fracture.

BACKGROUND: Our aim in this study was to identify the fibular footprint of the Anterior Inferior Tibiofibular Ligament (AITFL) and its relation to Wagstaffe fracture fragment size. METHODS: We examined 25 cadaveric lower limbs which were carefully dissected to identify the lateral ankle ligaments. The AITFL anatomy was compared to 40 Wagstaffe fractures identified from our ankle fracture database. RESULTS: The AITFL origin was from the anterior fibular tubercle with an average length of 21.61 mm (95% CI 20.22, 22.99). The average distance of the distal aspect of the AITFL footprint to the distal fibula margin was 11.60 mm (95% CI 10.49, 12.71). In the ankle fractures analyzed, the average length of the Wagstaffe fragment was 17.88 mm (95% CI 16.21, 19.54). The average distance from the distal tip of the fibula to the Wagstaffe fracture fragment was 21.40 mm (95% CI 19.78, 23.01). In total there were 22 syndesmosis injuries. There was no statistical difference in Wagstaffe fragment size between stable and unstable groups. CONCLUSION: The AITFL fibular origin was both larger and more distal than the Wagstaffe fracture fragments seen in our institution. Therefore, this suggests that a ligamentous failure will also have to occur to result in syndesmotic instability. The size of fracture fragment also did not confer to syndesmotic instability on testing. Level of Evidence - 3.

The impact of COVID-19 on foot and ankle surgery in a major trauma centre.

INTRODUCTION AND AIMS: COVID-19 has had a significant impact on orthopaedic surgery globally. This paper aims to evaluate the impact of COVID-19 on foot and ankle trauma in a major trauma centre. METHODS: A retrospective observational study of prospectively collected data was performed. All foot and ankle trauma patients over a 33 week period (1st December 2019-16th July 2020) were analysed. All patients with trauma classified by the AO/OTA as occurring at locations 43 and 81-88 were included. RESULTS: Over the 33 weeks analysed, there was a total of 1661 trauma cases performed; of these, only 230 (13.85%) were foot and ankle trauma cases. As percentage of cases during each period of lockdown, foot and ankle made up 15.20% (147 out of 967) pre-lockdown, 8.81% (17 out of 193) during lockdown and 13.17% (66 out of 501) post lockdown. This difference was statistically significant (p < .001). The most significant change in trauma management was the treatment of malleolar fractures. Further analysis showed that during the lockdown period 29 foot and ankle fractures were treated the same and 13 were treated differently, (i.e. 31% of fractures were treated conservatively, when the consultants preferred practice would have been surgical intervention). Of the 13 patients, 3 have had surgical management since lockdown has been eased. CONCLUSION: It is evident that the trauma case activity within foot and ankle was significantly reduced during the COVID-19 period. The consequences of change in management were mitigated due to a reduction in case load.

The influence of smoking on foot and ankle surgery: a review of the literature.

The effect of tobacco smoking on foot and ankle procedures is likely to be more pronounced when compared to other orthopaedic surgery. This is due to the peripheral nature of the vasculature involved. This paper reviews the current clinical evidence on the effects of smoking foot and ankle surgery. In the trauma setting, the evidence suggests that wound complications and non-unions are significantly higher in the smoking population. In the elective setting there is a significantly increased risk of non-union in ankle and hindfoot arthrodeses in smokers. In the setting of diabetes, ulceration rate in smokers is higher and there may be a higher risk of amputation.

The lateral transligamentous approach to the talar dome.

INTRODUCTION: Anatomic reduction of talar body fractures is critical in restoring congruency to the talocrural joint. Previous studies have indicated 43% talar body access with a single incision and without malleolar osteotomy. The aim of this study was to investigate the percentage talar body exposure when using the lateral transligamentous approach. METHODS: The lateral transligamentous approach to the talus was undertaken in 10 fresh frozen cadaveric specimens by surgeons inexperienced in the approach following demonstration of the technique. An incision was made on the anterolateral aspect of the ankle augmented by the removal of the anterior talofibular ligament (ATFL) and the calcaneofibular ligament (CFL) from their fibular insertions. A bone lever was then placed behind the lateral aspect of the talus and levered forward with the foot in equinus and inversion. A mark was made on the talar dome where an instrument could be placed 90 degrees to the talar surface. The talus was subsequently disarticulated and high-resolution images were taken of the talar dome surface. The images were overlain with a reproducible nine-grid division. Accessibility to each zone within the grid was documented using the mark made on the talar surface. ImageJ software was used to calculate the surface area exposed with each approach. RESULTS: The mean percentage area of talar dome available through the transligamentous approach was 77.3% (95% confidence interval 73.3, 81.3). In all specimens the complete lateral talar process was accessible, along with the lateral and dorsomedial aspect of the talar neck. This approach gives complete access to Zones 1, 2, 3, 5 & 6 with partial access to Zones 4, 8 & 9. CONCLUSION: The lateral transligamentous approach to the talus provides significantly greater access to the talar dome as compared to standard approaches. The residual surface area that is inaccessible with this approach is predominantly within Zones 4,7 and 8, the posteromedial corner. LEVEL OF CLINICAL EVIDENCE: V.

Posterior approaches to the ankle - an analysis of 3 approaches for access to the posterior malleolar fracture.

BACKGROUND: An anatomical study to determine what degree of access to the posterior distal tibia could be gained by using 3 different approaches; the posterolateral, the posteromedial and the medial posteromedial approaches. METHODS: A comparison study, between the anatomical dissection of 7 fresh frozen cadaveric lower legs and image analysis of CT data of posterior malleolar fractures from a prospectively collected database was conducted. All fractures have been classified using the Mason and Molloy classification. RESULTS: In comparing the posterior malleolar fracture fragment width to distal tibia width, the posterolateral fragment encompasses 60.1% (95% CI 56.8, 63.3) of the total width of the tibia. If the posteromedial fragment is included the fragments encompass the entire distal tibia (100%). In type 3 fractures, 81.4% (95% CI 75.5, 87.1) of the distal tibia width is involved. When comparing the fracture width to the approach, no approach achieves a complete exposure of the type 2B or 3 fracture patterns. The overall surface area of the type 2B and 3 fractures, is significantly greater than all the approaches. Considering the lateral to medial extent of the fracture, the posterolateral fragment mean width is 33% greater than what can be exposed by the posterolateral approach (mean 24.9 vs 16.8mm). In type 2B and 3 fractures, the horizontal exposure reduces to 39.8% and 47.6% respectively. In comparison, the PM approach exposes 47.6% of the type 2B fracture pattern and 57.1% of the type 3 fracture pattern and allows a preferable angle for hardware insertion. The MPM approach does not expose any of the posterolateral fragments in this study, however it does expose 92% (mean 21.9 vs. 23.8mm) of the medial to lateral width of a posteromedial fragment of a type 2B fracture. CONCLUSION: Each approach allows access to different parts and amounts of the posterior tibia. An understanding of and utilisation of these approaches can lead to adequate exposure for fixation of most posterior malleolus fracture patterns seen.

Pes Planus Deformity and Its Association With Hallux Valgus Recurrence Following Scarf Osteotomy.

BACKGROUND: Hallux valgus recurrence is an unsatisfactory complication, with many causes postulated. This study investigated the effect of pes planus on recurrence after scarf osteotomy. METHODS: A total of 183 feet were retrospectively reviewed. All patients were treated with a scarf osteotomy and if required Akin osteotomy. We measured preoperative lateral talus first metatarsal angle (T1MA) to study pes planus; an angle of under -4 degrees was considered pes planus. We measured pre and postoperative hallux valgus angle (HVA), intermetatarsal angle (IMA), and sesamoid location. In total 164 feet were suitable for inclusion, with follow-up of at least 6 months (10 males and 154 females, mean age: 52 years). RESULTS: Recurrence frequency (HVA greater than 15 degrees) was 27 feet (16%). Hallux valgus recurrence was not influenced by gender (P value = .66) or preoperative IMA (P value = .48). Preoperative HVA greater than 35 degrees was associated with increased frequency of recurrence (P value = .004). Those with T1MA less than -10 degrees demonstrated progression in HVA and deterioration in sesamoid location up to 6 months postoperatively (P value = .038). HVA did not progress beyond 6 months. The prevalence of recurrent hallux valgus with normal T1MA was 1%, in T1MA -4 to -10 degrees it was 29% and in T1MA less than -10 degrees it was 47% (P value <.001). Breaks in T1MA less than -4 degrees were found at the naviculocuneiform joint in 68% of feet in this series. CONCLUSION: The prevalence of hallux valgus recurrence correlated with the severity of pes planus. LEVEL OF EVIDENCE: Level III, retrospective cohort study.

Comparative Study of Spring Ligament Reconstructions Using Either Hamstring Allograft or Synthetic Ligament Augmentation.

BACKGROUND: Idiopathic flatfeet are usually caused by attenuation of the medial soft tissues rather than a lateral osseous deficiency. Debate continues on whether spring ligament attenuation or posterior tibial tendon (PTT) dysfunction is the initial driver for the deformity. Our comparative prospective study aimed to quantify the radiological and clinical outcomes of 2 techniques for spring ligament reconstruction using a hamstring graft or a synthetic ligament. METHODS: Seventeen spring ligament reconstructions (SLRs) were performed in 17 patients using synthetic ligament augmentation and 16 SLRs were performed using hamstring allograft in 13 patients. Additional procedures such as gastrocnemius recession, PTT advancement, flexor digitorum longus transfer, and calcaneal osteotomy were performed as required. A minimum of 12 months of follow-up was available for all cases. Radiographic analysis was performed with standardized parameters. RESULTS: Following SLR with synthetic ligament augmentation, all radiological parameters significantly improved (P < .05). Hamstring allograft SLR also demonstrated significantly improved radiographic parameters in all but Meary's line at final follow-up. At 12 months, patient outcome scores were significantly better in the synthetic ligament group. CONCLUSION: Reconstruction of the spring ligament using either hamstring allograft or synthetic ligament augmentation provided significant improvements in radiological alignment; however, superior patient-reported outcomes were found in the synthetic ligament augmentation group. LEVELS OF EVIDENCE: Level III, retrospective cohort study.

Posterior malleolar fractures: A CT guided incision analysis.

AIM: The aim of this study was to determine the most appropriate approaches for fixation of each type and fragment of posterior malleolar fractures. MATERIALS AND METHODS: A retrospective analysis of a prospectively collected database was performed on 141 posterior malleolar fractures. On the CT scan axial slice, a clock face was drawn using the posterolateral corner of the tibia as the centre and the Achilles tendon as the 6 o'clock axis. A box was then drawn from the fracture plane, with 90-degree lines corresponding to the medial perpendicular line (MPL) and lateral perpendicular line (LPL) extremity of the fracture and a central perpendicular line (CPL) (i.e. orthogonal central plane, for optimum screw placement). It was recorded where the MPL, LPL and CPL exited the clock face. All fracture patterns were further assessed by both senior authors regarding their choice of approach based on CPL and all variances resolved by discussion. RESULTS: The LPL was equivalent across the groups (except for the 2B medial fragments), indicating a consistent posterolateral corner fragment throughout the posterior malleolar sub types (p = 0.25). The medial aspect (MPL) of the type 1, type 2A and posterolateral fragments of type 2B were equivalent. The MPL of type 3 fractures was significantly more medial than type 1 and 2A fractures (p < 0.05), with the medial extremes of the type 2B posteromedial fragment being further medial. The majority of type 2B fractures (2/3rds) were determined to be best accessed through a combined posterolateral and medial posteromedial approach, with the other third via the posteromedial approach. Almost all type 3 fractures could be appropriately accessed through the PM approach. CONCLUSION: This study concludes that the extent of each subtype of posterior malleolar fractures are consistent. To fully expose each fracture differing incisions are necessary and should be in the skill mix for surgeons treating these fractures. LEVEL OF EVIDENCE: 4.

A review of the management and outcomes of tarsal navicular fracture.

Fractures of the navicular are uncommon. This review focusses on the anatomy, classification, surgical management, post-operative rehabilitation, and outcomes of tarsal navicular fractures, to better inform decision making for clinicians managing these injuries. This review does not discuss navicular stress fractures because of the differing aetiology compared to other fractures of the navicular.

Management of tibialis anterior tendon rupture: Recommendations based on the literature review.

Tibialis anterior tendon (TAT) rupture is a rare injury that commonly diagnosed late due to mild clinical signs and symptoms. Management of TAT rupture is a topic without a clear consensus in the literature. This current concept review tries to shed some light on the data and treatment. Our extensive literature review identified 81 case reports and case series from 1905 to 2018. Several reported management techniques with their advantages and disadvantages were analyzed and our treatment recommendations are given based on current available evidences. LEVELS OF EVIDENCE: IV.

Anatomy of the Lateral Plantar Ligaments of the Transverse Metatarsal Arch.

BACKGROUND: While the anatomy of the Lisfranc complex is well understood, the lateral tarsometatarsal ligamentous structures, in contrast, are less well studied. Our aim in this study was to identify an anatomical explanation as to why the second to fifth metatarsals function as a unit in homolateral and divergent midfoot injuries. METHODS: Eleven cadaveric lower limbs, preserved in formaldehyde, were examined at the University of Liverpool Human Anatomy and Resource Centre. Each of the lower limbs was dissected to identify the plantar aspect of the transverse metatarsal arch. RESULTS: On removal of the long plantar ligament, the peroneal longus tendon was visible, as was its insertion onto the first metatarsal base. A lateral Lisfranc ligament (which was a transverse suspensory metatarsal ligament) spanned between the bases of the second and fifth metatarsals in all specimens with an average length of 33.7 mm and width of 4.6 mm. This ligament has not previously been described. It was noted that in all specimens, the long plantar ligament blended with the lateral Lisfranc ligament. In addition to the lateral Lisfranc ligament, separate intermetatarsal ligaments were identifiable connecting each metatarsal. The long plantar ligament provided a connection through the lateral Lisfranc ligament connecting the transverse and longitudinal arches of the foot. CONCLUSION: We found a plantar ligament that provided connection through the long plantar ligament of both the transverse and the longitudinal arches. It spanned from the second to the fifth metatarsal, which we believe may explain that in some cases, lateral instability can be overcome when the middle column is stabilized. CLINICAL RELEVANCE: We suspect that in the majority of homolateral and divergent types of tarsometatarsal injuries that the lateral Lisfranc ligament remains intact and thus it has significant clinical ramifications.

Anatomy of the Insertion of the Posterior Inferior Tibiofibular Ligament and the Posterior Malleolar Fracture.

BACKGROUND: Our aim in this study was to identify the extent of the posterior inferior tibiofibular ligament (PITFL) insertion on the posterior tibia and its relation to intra-articular posterior malleolar fractures. METHODS: Careful dissection was undertaken on 10 cadaveric lower limbs to identify the ligamentous structures on the posterior aspect of the ankle. The ligamentous anatomy was further compared with our ankle fracture database, specifically posterior malleolar fracture patterns, demonstrating a rotational pilon etiology (Mason and Molloy type 2A and B). Computed tomography imaging was used to measure the dimensions of the fracture fragments. RESULTS: The superficial PITFL was found to have a transverse component and an oblique component. The average size of the tibial insertion was 54.9 mm (95% CI, 51.8, 58.0) from joint line and 47.1 mm (95% CI, 43.0, 51.2) transverse. From our database of ankle fractures involving the posterior malleolus, 80 Mason and Molloy type 2 fractures were identified for analysis. Of these, 33 were type 2A and 47 were type 2B. The posterolateral fragments had an average size of 26.3 mm (95% CI, 25.0, 27.7) height and 22.1 mm (95% CI, 21.1, 23.1) width. The posteromedial fragments had an average size of 22.0 (95% CI, 18.9, 25.1) height and 19.8 (95% CI, 17.5, 22.0) width. CONCLUSION: The superficial PITFL insertion on the tibia is broad. In comparison with the average size of the posterior malleolar fragments, the PITFL insertion is significantly larger. Therefore, for a posterior malleolar fracture to cause posterior syndesmotic instability, a ligamentous injury must also occur. CLINICAL RELEVANCE: Posterior syndesmotic instability results from injury to the PITFL. It has been widely reported that a posterior malleolar fracture will also give rise to posterior syndesmotic instability due to the insertion of the deep PITFL on the posterior tibia. On the contrary, in this paper, we have shown that the superficial PITFL insertion on the tibia is very large, much greater than the average size of the posterior malleolar fragments. Therefore, for a posterior malleolar fracture to cause posterior syndesmotic instability, a ligamentous injury will also have to occur.