Is there enough evidence to support hip capsular reconstruction? A systematic review of biomechanical studies

ABSTRACT The aim of this study was to review and summarize the available biomechanical data on hip capsular reconstruction to guide clinical decision-making. A literature search was completed in December 2020 using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines to identify biomechanical cadaver studies on hip capsular reconstruction, hip capsulectomy or hip capsular defect. The investigated parameters included maximum distraction force, capsular state affecting range of motion (ROM), rotation and translation. Four studies met al. the inclusion–exclusion criteria. The median effective force for resisting maximum distraction for the reconstruction state, capsular defect state and the intact state was 171, 111 and 206 N, respectively. The defect capsule force was significantly lower (P = 0.00438) than the intact capsule force. The reconstruction state had a higher distraction force than that of the capsular defect, but due to heterogeneity, the overall effect size was not statistically significant. The capsular reconstruction state reduced excess motion and the degree of instability compared to the capsular defect state but restored the hip close to its native capsular state in the cadaveric model. When compared to capsulectomy/defect state, hip capsular reconstruction significantly improved the rotational stability and effective force at maximum distraction and minimized translation. However, no conclusions can be made regarding the most effective protocol due to the high heterogeneity between the four studies. Further biomechanical studies are needed to test various types of grafts under the same protocol.

A Novel Technique for Soft-Tissue Defect Repair After Traumatic Rupture of the Extensor Hallucis Longus Tendon

Background Surgical repair of extensor hallucis longus (EHL) tendon rupture with a concomitant capsular defect has not been reported in the literature. This case presents a novel approach to EHL tendon rupture repair along with repair of a first metatarsophalangeal joint capsule defect. Methods A case study is presented of a 61-year-old man with a traumatic EHL tendon rupture and capsular defect treated with an EHL tendon turndown flap and tenodesis to the extensor hallucis brevis and capsularis tendons with autograft flap reconstruction of the first metatarsophalangeal joint capsule. Discussion A 61-year-old man presented with an acute traumatic EHL tendon rupture and first metatarsophalangeal joint capsule compromise after a chainsaw injury. He subsequently lost dorsiflexion of his hallux, and magnetic resonance imaging confirmed a 2.2-cm gap in the EHL tendon. He was treated with an EHL tendon turndown flap and tenodesis to the extensor hallucis brevis and capsularis tendons to reestablish dorsiflexion to the hallux. The injury was noted to infiltrate the first metatarsophalangeal joint capsule and was treated with an autograft of the first metatarsophalangeal joint capsule for a capsular defect. At 1-year follow-up the patient has regained dorsiflexion of the hallux and is back to activities such as snow skiing without pain. Conclusions Ruptures of the EHL tendon with first metatarsophalangeal joint capsule defects have not been reported in the literature. Herein, a novel approach was used to reestablish physiologic function to the EHL tendon and provide sufficient coverage of the first metatarsophalangeal joint.

Intraneural ganglion cysts of the lower limb

Background Intraneural ganglion cysts are rare. They affect the peripheral nerves. According to the most widely accepted theory (articular/synovial theory), the cysts are formed from a capsular defect of an adjacent joint, so that synovial fluid spreads along the epineurium of a nerve branch. This leads to diverse neurological symptoms. We will illustrate this disease based on three of our own cases. Methods Patients were examined between 2011 and 2018 using lower limb MRI. MRI scans were also performed for the follow-up examinations. Case studies and Discussion The patients had many symptoms. We were able to accurately detect the intraneural ganglion cysts on MRI and provide the treating surgeons with the basis for the operation to be performed. The success of surgical therapy depends on the resection of the nerve endings supplying the joint as the only way to treat the origin of the disease and prevent recurrence. Based on our case studies, we can support the commonly favored articular/synovial theory. Key Points: Citation Format

Effects of Capsular Reconstruction With an Iliotibial Band Allograft on Distractive Stability of the Hip Joint: A Biomechanical Study

Background: The capsular ligaments and the labral suction seal cooperatively manage distractive stability of the hip. Capsular reconstruction using an iliotibial band (ITB) allograft aims to address capsular insufficiency and iatrogenic instability. However, the extent to which this procedure may restore hip distractive stability after a capsular defect is unknown. Purpose: To evaluate the biomechanical effects of capsular reconstruction on distractive stability of the hip joint. Study Design: Controlled laboratory study. Methods: Eight fresh-frozen cadaveric hip specimens were dissected to the level of the capsule and axially distracted in 3 testing states: intact capsule, partial capsular defect, and capsular reconstruction with an ITB allograft. Each femur was compressed with 500 N of force and then distracted 6 mm relative to the neutral position at 0.5 mm/s. Distractive force was continuously recorded, and the first peak delineating 2 phases of hip distractive stability in the force-displacement curve was analyzed. Results: The median force at maximum distraction in the capsular reconstruction state (156 N) was significantly greater than that in the capsular defect state (89 N; P = .036) but not significantly different from that in the intact state (218 N; P = .054). Median values for distractive force at first peak (60 N, 72 N, and 61 N, respectively; P = .607), distraction at first peak (2.3 mm, 2.3 mm, and 2.5 mm, respectively; P = .846), and percentage decrease in distractive force (35%, 78%, and 63%, respectively; P = .072) after the first peak were not significantly different between the intact, defect, and reconstruction states. Conclusion: Capsular reconstruction with an ITB allograft significantly increased the force required to distract the hip compared with a capsular defect in a cadaveric model. To our knowledge, this is the first study to report an initial peak distractive force and to propose 2 distinct phases of hip distractive stability. Clinical Relevance: The consequences of a capsular defect on distractive stability of the hip may be underappreciated among the orthopaedic community; with that said, capsular reconstruction using an ITB allograft provided significantly increased distractive stability and should be considered an effective treatment option for patients with symptomatic capsular deficiency.