Generalised joint hypermobility leads to increased odds of sustaining a second ACL injury within 12 months of return to sport after ACL reconstruction

Key Points

1. Generalized joint hypermobility increases the risk for anterior cruciate ligament (ACL) second injury and is associated with inferior patient outcomes following ACL reconstruction.
2. Delaying return to sport to at least nine months can decrease the risk for ACL second injury.
3. Routine screening for generalized joint hypermobility can help clinicians to better understand their patients on an individual level.

BACKGROUND & OBJECTIVE

Second injuries following anterior cruciate ligament reconstruction (ACLR) continue to plague the sports medicine world, with rates being reported as high as 23% (1). Many of these injuries occur within the early return to sport (RTS) time frame, with research indicating a 7-fold reduction in risk for athletes who wait a minimum of nine months (2). Importantly, second injury statistics include ipsilateral and contralateral tears. Persistent underloading and alterations in mechanics place the unaffected knee at nearly the same risk level as the affected knee (3).

Ligamentous laxity and generalized joint hypermobility (GJH) have been proposed as important factors contributing to second injuries. Interestingly, GJH is more common amongst NCAA Division I athletes than the general population (4). GJH can be a double-edged sword for athletes. The increased joint range of motion (ROM) offers a competitive advantage, while the associated joint instability can increase injury risk (5). Fortunately, screening for GJH only takes 3-5 minutes and does not require any equipment. The Beighton scale provides a framework to place individuals on the GJH spectrum.

The authors of this paper sought to investigate the influence of GJH on ACLR outcomes.

Second injuries following anterior cruciate ligament reconstruction continue to plague the sports medicine world, with rates being reported as high as 23%.

The article serves as an important reminder for clinicians to use the Beighton scale and to educate their patients on its significance.

METHODS

Project ACL is a Swedish registry established in 2014 that focuses on ACL rehabilitation. This paper is the largest prospective study on the influence of GJH on ACLR outcomes. The registry collects ACLR patient data at set time intervals over a 2-year period: pre-operative, 10 weeks post op, and then 4, 8, 12, 18, and 24 months.

The authors searched a database of 4002 patients registered between 2014 and 2020. A total of 225 participants were eligible for inclusion. Inclusion criteria included Beighton scale testing, high activity levels, and competitive RTS goals.

The primary outcome of this study was second injury within 12 months.

RESULTS

• The GJH group (≥ 5 Beighton score) consisted of 50 participants (22.2%). The non-GJH group consisted of 175 participants (77.8%).

• Mean age of the GJH group was 22.3 years, and 25 years for the non-GJH group.

• Time from injury to surgery for the GJH group was 4.9 months, and 8.9 months for the non-GJH group.

• RTS for the GJH group was 9.2 months vs. 11.5 months for the non-GJH group.

• ACL-RSI at RTS was 63.3 for the GJH group vs. 65.4 for the non-GJH group.

• The GJH group had 68% hamstring autograft and 32% patellar tendon autograft. The non-GJH was 79.4% vs. 18.3%, respectively, as well as 2 allografts and 1 other.

• Second ACL injury within 12 months was 14% in the GJH group vs. 2.9% in the non-GJH group, indicating a 5-fold increase for the GJH group.

• Within the 12-month time frame, the GJH group experienced 4 ipsilateral and 3 contralateral injuries. The non-GJH group experienced 4 ipsilateral and 1 contralateral injury.

• Second ACL injury within 24 months was 38% in the GJH vs. 10% in the non-GJH group.

LIMITATIONS

The results of this paper are strongly influenced by the individual rehabilitation experiences of both groups. The GJH group (9.2 months) had a significantly earlier RTS compared to the non-GJH group (11.5 months), calling into question the primary outcome RTS cut-off of 12 months. The scarcity of information regarding concomitant intra-articular injuries and specifics of the rehabilitation programs further add to the ambiguity of results. Over 1300 eligible patients with sporting goals were excluded due to a lack of Beighton score, indicating an area of growth for clinical exam standards.

CLINICAL IMPLICATIONS

GJH assessment is helpful for prioritizing interventions, as more mobile patients are less likely to exhibit ROM restrictions, and might require less stretching and mobilization to regain sufficient ROM. Moreover, this population may benefit from greater emphasis on eccentric strength, due to their need to decelerate their joints through larger ROM.

GJH can also influence joint ROM goals post-op ACLR. Striving for hyperextension ROM symmetry is not recommended when the unaffected knee has > 10° of hyperextension, as evidence points toward an increased risk of graft failure and rotary instability (6,7). On the contrary an individual with a 0/9 Beighton score may benefit from earlier ROM-focused interventions and a shorter immobilization period following a surgery that poses a risk of contracture or post-operative stiffness.

Second injury rates in the 24-month follow up were shown to be higher than average (38%) for the GJH group and lower than average (10%) for the non-GJH group. Notwithstanding the multifactorial nature of ACL rehab, these numbers are compelling.

The article serves as an important reminder for clinicians to use the Beighton scale and to educate their patients on its significance. GJH affects both contractile and inert tissue, as alterations observed in collagen fibers influence the structure of connective tissue. GJH is thought to exacerbate forces placed on intra-articular ligaments and joint stabilizing structures. GJH is a risk factor for many more pathologies, including patellar instability and multi-directional shoulder instability (8,9). Patients with GJH will benefit from careful consideration when appraising risk and determining their RTP goals.

+STUDY REFERENCE

Zsidai B, Piussi R, Thomeé R, Sundemo D, Musahl V, Samuelsson K, Senorski E (2023) Generalised joint hypermobility leads to increased odds of sustaining a second ACL injury within 12 months of return to sport after ACL reconstruction. British Journal of Sports Medicine, Published Online First.

SUPPORTING REFERENCE

1. Wiggins AJ, Grandhi RK, Schneider DK, et al. (2016). Risk of secondary injury in younger athletes after anterior cruciate ligament reconstruction: a systematic review and meta-analysis. Am J Sports Med.
2. Beischer S, Gustavsson L, Senorski EH, et al. (2020). Young athletes who return to sport before 9 months after anterior cruciate ligament reconstruction have a rate of new injury 7 times that of those who delay return. J Orthop Sports Phys Ther.
3. Fontenay BP, Roy JS, d, Plemmons M, Willy R. (2023). Knee joint underloading does not evolve after a two-week reintroduction to running program after anterior cruciate ligament reconstruction. Physical therapy in Sport.
4. Reuter, P. R., & Fichthorn, K. R. (2019). Prevalence of generalized joint hypermobility, musculoskeletal injuries, and chronic musculoskeletal pain among American university students. Peer J.
5. Hegedus EJ, Michener LA, Seitz AL. (2020). Three Key Findings When Diagnosing Shoulder Multidirectional Instability: Patient Report of Instability, Hypermobility, and Specific Shoulder Tests. J Orthop Sports Phys Ther.
6. MARS Group, Cooper DE, Dunn WR, et al. (2018). Physiologic preoperative knee hyperextension is a predictor of failure in an anterior cruciate ligament revision cohort: a report from the Mars group. Am J Sports Med.
7. Guimarães TM, Giglio PN, Sobrado MF, et al. (2021). Knee hyperextension greater than 5 degrees is a risk factor for failure in ACL reconstruction using hamstring graft. Orthop J Sports Med.
8. Homere, A., Bolia, I. K., Juhan, T., Weber, A. E., & Hatch, G. F. (2020). Surgical Management of Shoulder and Knee Instability in Patients with Ehlers-Danlos Syndrome: Joint Hypermobility Syndrome. Clinics in orthopedic surgery.
9. Hiemstra, L. A., Kerslake, S., Kupfer, N., & Lafave, M. R. (2019). Generalized joint hypermobility does not influence clinical outcomes following isolated MPFL reconstruction for patellofemoral instability. Knee surgery, sports traumatology, arthroscopy : official journal of the ESSKA.