A Case-Control Study of 3D vs 2D Weightbearing CT Measurements of the M1-M2 Intermetatarsal Angle in Hallux Valgus

Role of lateral soft tissue release in percutaneous hallux valgus surgery: a systematic review and meta-analysis of the literature

BACKGROUND

It is unclear whether lateral soft tissue release (LSTR) is required as part of percutaneous hallux valgus (PHV) surgery. The primary aim of this systematic review was to assess whether LSTR reduces the risk of recurrence of hallux valgus deformity. The secondary aims were to assess if LSTR increases the risk of complications, improves the clinical outcome and leads to a greater radiographic correction.

METHODS

We performed a PRISMA-compliant PROSPERO-registered systematic review, pooling clinical papers reporting results after PHV surgery into two categories (PHV with (Group 1, G1) and without LSTR (Group 2, G2)) and comparing them. Data regarding the study design, demographics, the surgical procedure and the clinical and radiological outcome were extracted and compared. Risk of bias was assessed using the modified Coleman Methodology Score (mCMS).

RESULTS

Sixteen studies were selected (G1:594 feet; G2:553 feet). The pooled proportion of recurrence at a minimum 21-month follow-up (2%, 95%CI 0-3 vs 2%, 95%CI 0-5; p = 0.70) did not differ in the two groups. Similarly, the pooled proportion of complications (27%, 95%CI 17-38 vs 25%, 95%CI 12-37; p = 0.79) was similar. The pre- (p = 0.23) and post-operative AOFAS scores (p = 0.16), the pre-(HVA: p = 0.23) (IMA: p = 0.94) and post-operative radiological angles (HVA: p = 0.47) (IMA: p = 0.2) and the methodological quality of studies (p = 0.2) did not differ either between G1 and G2.

CONCLUSION

There is no evidence that LSTR performed during percutaneous HV surgery reduces the risk of recurrence of the deformity at a mean 4-year follow-up nor improves the clinical and radiological outcome.

LEVEL OF EVIDENCE

Level IV systematic review of Level I to IV studies.

Reliability of Cone Beam Weightbearing Computed Tomography Analysis of Total Ankle Arthroplasty Positioning and Comparison to Weightbearing X-Ray Measurements

BACKGROUND

The current reference standard for postoperative evaluation of total ankle arthroplasty (TAA) positioning, weightbearing radiography (WBXR), is subject to technical bias. Weightbearing cone beam computed tomography (WBCT) enables visualization of the foot's complex 3-dimensional (3D) structure under standing load. To date, no WBCT-based system for TAA positioning has been validated. The purpose of this study was to (1) assess TAA positioning using WBCT 3D models and (2) evaluate the agreement levels between 2 raters and thus evaluate the intermethod reliability with respect to WBXR.

METHODS

Fifty-five consecutive patients were retrospectively reviewed. Two raters independently created a 3D WBCT model using dedicated software and recorded the following measurements: α angle, tibiotalar surface angle (TSA), hindfoot angle (HFA), tibiotalar ratio (TTR), β angle, γ angle, and Φ angle. Measurements were repeated 2 months apart in similar, independent fashion and compared to WBXR. Interobserver, intraobserver, and intermethod agreements were calculated.

RESULTS

All 7 measurements showed good to excellent intraobserver and interobserver reliability (ICC 0.85-0.95). The intermethod (WBCT vs WBXR) agreement showed good agreement for the γ angle (ICC 0.79); moderate agreement levels for the α angle, TSA angle, β angle, and TTR (ICC 0.68, 0.69, 0.70, and 0.69, respectively); poor agreement for the HFA (ICC 0.25); and negative agreement for the φ angle (ICC -0.2).

CONCLUSION

Position analysis of TAA using WBCT demonstrated good to excellent interobserver and intraobserver agreement and can be reliably used. Additionally, a negative to moderate agreement between standard WBCT and standard WBXR was found.

LEVEL OF EVIDENCE

Level III, retrospective study.