Journal of Experimental Orthopaedics最新文献

Purpose

The purpose of this study was to determine the impact of (1) healthy versus arthritic knees and (2) partial versus complete release of the superficial medial collateral ligament (sMCL) on tibiofemoral compartment pressures at varying mechanical axis alignments following medial open-wedge high tibial osteotomy (MOW-HTO).

Methods

Contact pressure (CP) was measured in seven cadaver knees (four healthy; three arthritic) under 1000 N axial load. Tests were conducted at constitutional alignment and MOW-HTO alignment corrections to 50%, 55%, 60% and 65% of the tibial plateau width (TPW) with the sMCL intact and repeated at each alignment following a partial and complete sMCL release. Linear mixed-effects models assessed differences in tibiofemoral CP with factors (1) arthritic status and alignment and (2) alignment and sMCL condition. Main effects were assessed for each factor followed by pairwise comparisons when significant.

Results

Medial CP in healthy and arthritic knees did not differ in response to varying alignment corrections (p = 0.103). The interaction of alignment and sMCL condition was not significant (p = 0.61). With the sMCL intact, altering alignment was found to significantly impact medial CP (p = 0.01). Medial CP significantly decreased from constitutional alignment to 55% and 60% of TPW by 19.0% and 13.9%, respectively (p = 0.02; p = 0.02). Additionally, medial CP at 55% of TPW was found to be 6.6% lower than at 50% of TPW (p = 0.046) and 10.4% lower than at 65% TPW (p = 0.03). sMCL release did not impact medial CP (p = 0.24) but significantly increased lateral CP by 10.8% when completely released (p < 0.001).

Conclusion

The presence of medial compartment arthritis may not be a significant factor in the loading biomechanics of cadaver knees secondary to MOW-HTO corrections. MOW-HTO correction to 55% of TPW was most effective in decreasing medial CP. sMCL release did not impact medial CP; however, it significantly increased lateral CP when the sMCL was completely released.

Level of Evidence

NA, cadaveric study.

An injury to the anterior cruciate ligament (ACL) can be sustained in sports participation during situations such as offensive cutting, landing from a jump, or defensive pressing. Despite treatment with surgical reconstruction and/or rehabilitation, only 55%–84% of patients return to sport (RTS) after treatment, and second ACL injury rates remain as high as 25% in young athletes. To reduce the risk of second ACL injury, clinicians commonly use muscle strength tests, hop tests, and patient-reported outcomes (PROs) to evaluate readiness for RTS. These tools have become central in clinical decision-making, yet significant challenges remain. Current tests typically rely on limb symmetry index (LSI) thresholds, with ≥90% LSI commonly recommended as a clearance criterion for RTS. However, these cut-offs have shown poor predictive value for second ACL injury risk and may be misleading. The LSI also fails to account for pre-injury strength, bilateral deficits, or compensatory movement strategies. Hop tests provide additional insights into explosiveness and load absorption but emphasise distance or repetitions rather than movement quality, missing key biomechanical risk factors. Similarly, while PROs aim to capture the psychological dimension of recovery, they cannot be used in isolation to determine readiness for RTS. Collectively, these evaluation tools provide only snapshots of recovery and do not adequately reflect the chaotic, multidimensional demands of sport. The research gap lies not in the absence of tests, but in their limited transferability, standardisation, and contextual relevance. Current tests should not be viewed as a simple pass-or-fail clearance point, but as guidance for informed decision-making in rehabilitation. Continuous evaluation across physical and psychological domains can help clinicians tailor progression, motivate patients, and support safer transitions toward sport. This narrative review explores the current state, limitations, and future directions of RTS testing in order the bridge the gap between clinical measures and the chaotic, high-demand realities of sport.

Level of Evidence

Level III.

Purpose

This study evaluated the comparative efficacy of two guiding devices in positioning the femoral tunnel in the ‘Isometric, Direct insertion, Eccentrically located, Anatomical, Low tension’ (I.D.E.A.L.) zone during anterior cruciate ligament reconstruction.

Methods

A retrospective analysis was conducted on 64 patients. Group A (32 cases) used traditional tools, while Group B (32 cases) used the modified locator. Postoperative three-dimensional computed tomography reconstructions of the femoral condyle were performed, and tunnel position (using the quadrant method) and the distance from the tunnel's posterior edge to the lateral condyle posterior wall were measured. Statistical analysis was performed to compare the differences between the two groups.

Results

The mean femoral tunnel centre positions were 30.3% ± 4.5% (deep–shallow) and 25.5% ± 9.6% (high–low) in Group A, and 25.9% ± 3.9% (deep–shallow) and 26.6% ± 5.8% (high–low) in Group B. The ideal I.D.E.A.L. tunnel centre was defined at (28.4, 22.2). No significant difference in dispersion was observed between the two groups. But the tunnel centre in Group B is more concentrated near the posterior region of the femoral footprint. The distance from the posterior tunnel edge to the posterior wall was 3.5 ± 1.7 mm in Group A and 2.2 ± 1.0 mm in Group B, showing a significant difference. Each group had 1 case of the posterior wall rupture; the rupture rate did not differ significantly between the groups.

Conclusion

The modified locator facilitates femoral tunnel placement closer to the posterior wall, which promotes the biomechanical conditions required for optimal graft isometry and low tension.

Level of Evidence

Level IV and V, retrospective study.

Purpose

To evaluate the validity and reliability of the French version of the Quick Foot and Ankle Ability Measure (Q‑FAAM‑F) in French‑speaking patients with chronic lateral ankle instability (CLAI).

Methods

We conducted a prospective observational cohort in a sports surgery centre with repeated assessments preoperatively, and at 3 and 6 months postoperatively; the primary analysis was cross‑sectional at 6 months. Consecutive CLAI patients undergoing anatomic lateral ankle ligament reconstruction (AALR) were included. Patients completed the Q‑FAAM‑F (12 items derived from the validated French FAAM) alongside the full FAAM, FAOS, ALR‑RSI, CAIT and VAS‑pain. Internal consistency (Cronbach's α), item–total and inter‑item correlations, and construct validity (Pearson's r) were calculated. Discriminant validity used ROC analyses for CLAI status (CAIT < 24) and return to sport (RTS), defined on the RTS continuum as return to the pre‑injury sport at any level at 6 months and treated as an external clinical variable.

Results

Among 275 patients (56% male; median age 32 years), Q‑FAAM‑F showed excellent internal consistency (α = 0.96) and strong item–total correlations (mean r ≈ 0.65). Convergent validity was strong with the FAAM (r = 0.95) and with FAOS and ALR‑RSI; divergent validity was supported by the absence of correlation with CAIT of the nonoperated limb. ROC AUC for CLAI status and RTS were high; optimal cut‑offs were 78.1/100 (CLAI: sensitivity 81.3%, specificity 85.4%) and 80.2/100 (RTS: sensitivity 75.4%, specificity 87.9%).

Conclusion

The Q‑FAAM‑F is a valid and reliable PROM for French‑speaking CLAI patients, suitable for clinical practice and research. Precise AUC‑based thresholds may support clinical decision‑making at 6 months.

Level of Evidence

Level III.

Purpose

Multiple revision total knee arthroplasty (rTKA) remains highly challenging due to severe bone defects, which often render standard implants unsuitable. This study aimed to evaluate the clinical outcomes, survivorship and complication rates of customised knee implants used in aseptic one-stage rTKA for patients with severe bone defects.

Methods

This study included 16 patients who underwent 18 one-stage rTKAs using custom-made implants due to aseptic loosening between 2016 and 2023. Conventional revision systems failed to provide appropriate femoral or tibial fixation due to severe conical longitudinal bone defects classified as Anderson Orthopaedic Research Institute (AORI) type III. Clinical outcomes were assessed using the knee injury and osteoarthritis outcome score (KOOS), Oxford knee score (OKS), visual analogue scale (VAS) for pain, range of motion (ROM), walking time and procedure-related complications. Implant costs were compared between customised and standard implants.

Results

Mean follow-up was 51 months (range, 24–100), with patients having an average of five previous surgeries (range, 2–8). During follow-up, three patients (17%) reported complications: one periprosthetic fracture, one periprosthetic joint infection and one failure of the modular stem component. Mean KOOS improved from 31 to 80 (p < 0.001), OKS from 47–32 points (p < 0.001) and pain on the VAS decreased from 8.1 to 3.1 (p < 0.001).

Conclusions

Customised implants for one-stage rTKA present a promising cementless fit-and-fill fixation option for patients with severe longitudinal bone defects, particularly when standard knee revision implants, including cones and sleeves, are no longer suitable. Yet, these results are just midterm and small sample size-based and therefore long-term results in larger patient numbers need to be awaited before a final conclusion can be made.

Level of Evidence

Level IV.