OBJECTIVES: To evaluate soft tissue complications and the incidence of neurovascular bundle (NVB) injury following the modified posteromedial approach (moPMA) for posterior malleolar (PM) fractures, and to describe its indications in clinical practice.

METHODS:
Design: Retrospective, observational case-series study.
Setting: Single center with a dedicated foot and ankle trauma unit.
Patient Selection Criteria: Consecutive adult patients who underwent open reduction and internal fixation (ORIF) of PM fractures (AO/OTA 44 or 43) using the moPMA between 2014 and 2024. Exclusion criteria were open or pathological fractures, prior surgery at other institutions, or incomplete clinical records.
Outcome Measures: Primary outcomes were incidence of soft tissue complications and NVB injuries, graded according to the modified Clavien–Dindo classification for foot and ankle surgery.
Secondary outcomes included fracture classification according to AO/OTA and Bartonícek–Rammelt, associated procedures and approaches, surgical staging, fixation type, follow-up, and use of intraoperative imaging.

RESULTS: The mean age was 47 years (range 18–83 years), there were 14 male and 40 female patients. The mean time from injury to surgery was 5.9 days. According to the Bartonícek–Rammelt classification, 51.9% were type C, 31.5% type B, and 14.8% type D. Most cases (77.8%) were AO/OTA 44B3. The moPMA was used in the first surgical stage in 77.8% of cases. A second approach was required in 90.7%, most commonly for fibular fixation through a lateral approach (70.4%). Associated procedures were performed in 92.6%, with fibular osteosynthesis being the most frequent (66.7%). Fixation was plate-based in 92.5%. The mean follow-up was 63.1 6 31.4 months. Hardware removal of the posterior fixation was performed in 37.1%. Soft tissue complications occurred in 4 patients (7.4%), all classified as grade IA. No NVB injuries or tibialis posterior tendon contractures were reported.

CONCLUSIONS: The modified posteromedial approach for fixation of posterior malleolar fractures demonstrated low complication rates and no neurovascular injuries, supporting its use in a wide range of posterior malleolar fractures. KEY WORDS: modified posteromedial approach, moPMA, posterior malleolar fractures, soft tissue complications

LEVEL OF EVIDENCE: Level IV. Retrospective. Descriptive. Observational case-series study.

Abstract

Background Stress fractures of the fifth metatarsal (M5) are common among individuals engaging in repetitive impact activities or patients with preexisting deformities. Compared with patients who have traumatic fractures, those with stress fractures often develop delayed union, nonunions, or recurrence. Risk factors such as hindfoot varus and foot adduction have been implicated. The recent advent of weightbearing CT enables the study of specific bone density and orientation characteristics that have not, to our knowledge, previously been explored. Such tools could detect higher risk patients and help trigger potential preventive measures.

Questions/purposes Do patients with an M5 stress fracture present altered three-dimensional orientation and alignment parameters compared with an age- and sex-
matched control group? (2) Do the feet and M5s of patients with an M5 stress fracture present different foot ankle offset (FAO) parameters compared with the control group? (3) Do the M5s of patients with an M5 stress fracture present with altered bone density patterns compared with the control group, and is a clinically relevant threshold identifiable?

Methods This institutional review board–approved retrospective case-control study analyzed 15 feet of patients with M5 stress fractures and 15 feet of a control group using weightbearing CT. Between February 2022 and May 2024, a total of 74 patients with available weightbearing CT scans were treated for an M5 fracture. Among those patients, we considered 77% (57) of proximal fractures as potentially eligible. Of those patients, 39% (22 of 57) were included; a further 32% (7 of 22) were later excluded because of metal artifact conflicting with M5 bone density assessment, leaving 68% (15 of 22) for analysis here. Controls were selected from our weightbearing CT archive, matched for age and sex and excluded if any foot disorder or prior intervention was identified. Accordingly, there were seven males and eight females in each group, and five and nine left sides, respectively, in the stress fractures and control groups. The mean 6 SD age was 53 6 13 years for the stress fractures group versus 51 6 12 years for controls. Mean 6 SD BMI was 34.4 6 10.2 kg/m 2 for the stress fractures group and 36.8 6 8.2 kg/m 2 for controls. For the first study question, M5 orientations and baseline foot alignment parameters were evaluated based on Digital Imaging and Communications in Medicine (DICOM) data sets using weightbearing CT software. For the second study question, weightbearing CT software was used to measure the FAO and assess the spatial relationship of the M5 with the foot tripod. For the third study question, segmentation and bone density measurements, using Hounsfield units (HUs), were performed with commercially available and open-source software. Receiver operating characteristic analysis with the Youden index was performed to determine the sensitivity and specificity of the HU M5/HU talus density ratio for identifying stress fractures.

Results The stress fractures group exhibited a lower M5 base height at mean 6 SD 9 6 3 mm versus 12 6 3 mm (p = 0.045), greater ground contact frequency (11 of 15 versus 0 of 15 for the control group; p < 0.001), and an increased median (range) M5/M4 length ratio of 1.06 (0.95 to 1.14) versus 1.01 (0.97 to 1.10) for controls (p = 0.04). Hindfoot varus and foot adduction were associated with stress fractures, as indicated by altered hindfoot alignment and tarsometatarsal angles. The stress fractures group demonstrated a mean 50% increase in the HU M5/HU talus density ratio, at a median (range) of 1.52 (0.9 to 2.3) versus 1.02 (0.97 to 1.1) (p < 0.001). A relative increase by a factor of 1.2 in the HU M5/HU talus density ratio was associated with the stress fractures group with 80% sensitivity and 94% specificity.

Conclusion Stress fractures of the M5 are known to be associated with hindfoot varus and forefoot adductus. The present study adds that these injuries may also be associ-
ated with reduced base height, increased plantarflexion, a longer M5, and higher bone density. Future prospective studies could investigate whether using a threshold of 1.2 for the HU M5/HU talus density ratio to trigger early preventive measures could help decrease the occurrence of stress fractures.

Level of Evidence Level III, prognostic study.

Background: Excessive laxity of the first ray has been implicated in various foot disorders. Accurate assessment is critical to define the most appropriate treatment. However, assessment currently depends largely on clinical examination and lacks objectivity. We evaluated the performance of an automated electromechanical tool developed to measure the relative dorsal mobility of the medial column compared to the lateral rays, and assessed the intra- and inter-examiner reliability of this device.

Methods: Two examiners assessed 30 feet of 17 volunteers. Data were collected 15 times on each foot. The intraclass correlation coefficient (ICC), Bland-Altman (B&A) graphical analysis, and the standard error of measurement (SEM) were calculated.

Results: Inter-rater and intra-rater ICC values (>0.9) were excellent. The Bland-Altman analysis revealed a mean bias of 0.07 mm between examiners.

Conclusion: This novel electromechanical device has demonstrated reliability in measuring first ray laxity, supporting its use in future studies aimed at quantifying first ray hyperlaxity.

Level of evidence: Level II, Prospective Reliability Study.

Early radiologic outcome and technical details of MIS
bunionectomy using a guided trajectory system is reported here.
From April 2022 to March 2023, 20 consecutive minimally invasive
bunionectomies were performed on 17 female patients (bilateral in 3
patients) with an average age of 63.6 (range: 46 to 82). The mean
IMA improved from 14.3 degrees (SD: 3.2) to 4.6 degrees (SD: 2.0),
HVA from 28.2 degrees (SD: 6.3) to 6.7 degrees (SD: 2.8), DMAA
from 16.6 degrees (SD: 5.6) to 6.6 degrees (SD: 1.8). Preoperatively,
17 feet (89.5%) were in TSP grades 2 and 3. Postoperatively, 19 feet
(95%) improved to either TSP grades 0 and 1. The mean duration of
operative time was 50 (SD: 9.25, range: 23 to 65) minutes. No
intraoperative complications were reported. Overall, this study
provides valuable insights into the benefits of using a guided trajectory
system to improve the success of bunion correction surgeries.
Level of evidence: Level 4.