Generalized Hypermobility, Knee Hyperextension, and Outcomes After Anterior Cruciate Ligament Reconstruction: Prospective, Case-Control Study With Mean 6 Years Follow-up

Abstract

To determine whether generalized hypermobility and contralateral knee hyperextension affect failure rates and patient-related outcomes after anterior cruciate ligament reconstruction (ACLR). A total of 226 consecutive patients presenting with acute ACL tears were prospectively evaluated for generalized hypermobility by a modified Beighton criteria. Minimum 2-year follow-up was achieved for 183 knees (81%). Patients underwent ACLR with either bone-patellar-tendon (BPTB) autograft (n= 46), quadrupled hamstring (HT) autograft (n= 85), or allograft tissue (n=52). KT-1000 measurements, International Knee Documentation Committee (IKDC), Cincinnati, and Lysholm scores were obtained. Forty-one of 183 consecutive patients were categorized as hypermobile. At mean 6years' follow-up (range 2-12.5years), IKDC (P= .003), Cincinnati (P= .001), and Lysholm scores (P < .001) were significantly better in the Non-Hypermobile group for patients with an intact graft. The failure rate was higher in the Hypermobile group (10knees, 24.4% failure rate) compared with the Nonhypermobile group (11 knees, 7.7% failure rate) (P= .006). The overall ACL injury rate (ACL graft injury, excessive graft laxity, plus contralateral ACL tear) was higher in the Hypermobile group (34.1%) compared with the Nonhypermobile group (12.0%) (P= .002). Heel height >5cm(P= .009) and fifth metacarpophalangeal (MCP) extension >90° (P= .006) were independently predictive of failure for the entire study population. Graft failure rates were higher and inferior subjective outcomes were observed after ACLR in patients with generalized hypermobility. Heel height and fifth MCP hyperextension were most predictive of ACL injury/reinjury and poorer outcome scores. Nearly one-third of hypermobile patients sustained a contralateral ACL tear, ipsilateral graft failure, or had excessive graft laxity. Level III, case control study.