Purpose. The aim of the present study was to investigate the relationship between generalised ligament laxity and requirement for revision ACL reconstruction. Materials and methods. 126 patients undergoing primary ACL reconstruction were included in the study along with 35 patients undergoing revision ACL surgery. 62 patients without any knee ligament injury formed an age and sex matched the control group. The Beighton score was used to quantify the ligamentous laxity in all cases with a score more than 4 classified as having generalised ligamentous laxity. The revision ACL patients were evaluated to identify technical errors at the time of the primary procedure or subsequent traumatic injury that could have contributed to primary graft failure. Results. The primary ACL surgery group was associated with an increased generalised ligamentous laxity compared to the control group and this was statistically significant (p < 0.05). Similarly the revision surgery group was also associated with increased generalised ligamentous laxity compared to the control group (p < 0.05). The revision ACL surgery group was also associated with increased generalised ligamentous laxity when compared to the primary ACL surgery group but this did not quite achieve statistical significance (p = 0.058). There was a subgroup within the revision cohort, who had a failure of the original surgery due to biological failure of the primary graft. The incidence of generalised ligament laxity in this group was significantly higher than the primary surgery group (p < 0.05). Conclusion. The findings of the study suggest a clear relationship between generalised ligamentous laxity and ACL injury. The study also highlights a link between generalised ligamentous laxity and requirement for revision ACL surgery. Based on the results of our study we feel that in the presence of GLL an autogenous graft may not be the best mode of reconstruction for either primary of revision ACL reconstruction. A case could be made for preferring allografts over autografts for these patients to reduce the rate of graft failure. Further prospective studies comparing allograft and autorgraft failure rates in patients undergoing primary and revision ACL are required to confirm our observations

Purpose: This study was performed to assess the incidence of generalized ligament laxity in patients undergoing revision ACL reconstruction. Methods and Results: Prospective data was collected for 40 patients undergoing revision ACL reconstruction, between 2004 and 2009 under the care of a single orthopaedic consultant including demographic details, graft used during primary and revision ACL reconstruction and causes of graft failure. Clinical examination was used to assess the ligament laxity using the Beighton score. Laxity is scored on a 0–9 scale. Scores of 4 or above are indicative of generalized ligament laxity. Brighton criteria is used to diagnose Benign Joint Hypermobility Syndrome (BJHS) and use signs and symptoms along with Beighton score. The most common graft used was a quadruple hamstring in 23 patients (57%). The causes of graft failure were trauma in 22 patients (55%), biological in 17 patients (42%) and infection in 1 patient (2.5%). The revision ACL graft was patella tendon in 23 patients (57%), allograft tendon was used in 11 patients (28%) and quadruple hamstring was used in 4 patients (10%). The average Beighton score for these patients was 3 with a range from 0–9. 20 patients (50%) in this group had a Beighton score of 4 or more. Only 6 patients (15%) fulfilled the Brighton criteria for BJHS. Conclusion: We found that there is a high incidence (50%) of generalized ligament laxity in patients undergoing revision ACL reconstruction. Biological failure is common (42%) in these patients after using autogenous tendons. We recommend the use of allograft for primary ACL reconstruction in patients with generalized ligament laxity

Purpose: This study was performed to assess the incidence of generalized ligament laxity in patients undergoing revision shoulder stabilization. Methods and Results: Prospective data was collected for 21 patients undergoing revision shoulder stabilization and 43 patients with clavicle fractures as a control group, between 2004 and 2009 under the care of orthopaedic surgeons at the Royal Infirmary of Edinburgh including demographic details, type of primary stabilization and causes of failure. Clinical examination was used to assess the ligament laxity using the Beighton score. Laxity is scored on a 0–9 scale. Scores of 4 or above are indicative of generalized ligament laxity. Brighton criteria is used to diagnose Benign Joint Hypermobility Syndrome (BJHS) and use signs and symptoms along with Beighton score. The most common primary procedure for shoulder instability was open stabilization in 15 patients (75%). The most common cause of failure was trauma in 14 patients (67%). The mean age was 29 years with a range from 22–58 years. There were 16 males and 5 females. The average Beighton score for patients undergoing revision shoulder stabilization was 2.8 with a range from 0–7. 13 patients (61%) in this group had a Beighton score of 4 or more as compared to 12 patients (27%) in the control group. This difference was statistically significant with a P value of 0.018. 11 patients (52%) fulfilled the Brighton criteria for BJHS. Conclusion: We found that there is a high incidence (61%) of generalized ligament laxity in patients undergoing revision shoulder stabilization. Trauma is a common (67%) cause of failure in these patients. Patients with generalized ligament laxity should be made aware about the high failure rate after shoulder stabilization at their primary surgery and appropriate advice about rehabilitation should be given

Introduction: This study was performed to assess the incidence of generalized ligament laxity in patients presented with 1st time anterior shoulder dislocation. Patients and Methods: Prospective data was collected for patients presented with 1st time anterior shoulder dislocation and clavicle fracture as a control group between Aug 2008 and Feb 2009 under the care of a specialist shoulder surgeon. Data included demographic details, mechanism of injury and generalized ligament laxity using Beighton score. Laxity is scored on a 0–9 scale. Scores of 4 or above are indicative of generalized ligament laxity. Brighton criteria was used to diagnose Benign Joint Hypermobility Syndrome (BJHS). Results: Data was collected for 44 patients with first time anterior shoulder dislocation and 43 patients with clavicle fracture. There was no difference in the demographics of the groups. There were 40 male (91%) and 4 (9%) female patients in the dislocation group. Mean age was 25 years with a range from 15–55. Most common cause of shoulder dislocation was sports related injuries in 26 patients (60%). The average Beighton score for dislocation group was 3.6 with a range from 0–9 as compared to 2.1 with a range from 0–7 in the control group. Twenty one patients (48%) in the dislocation group had a Beighton score of 4 or more indicating generalized ligament laxity as compared to 12 patients (28%) in the control group. This difference was statistically significant with a P value of 0.009. Six patients (14%) fulfilled the Brighton criteria for BJHS in the dislocation group as compared to 3 patients (7%) in the control group. Conclusion: We found that there is a high incidence (48%) of generalized ligament laxity in patients presented with first time anterior shoulder dislocation. Appropriate advice should be given to these patients about rehabilitation, risk of recurrent dislocations and timing of shoulder stabilization

In 11 paediatric patients (seven girls and four boys, from 12 to 15 years old) with unilateral obligatory patellar dislocation and ligamentous laxity vastus medialis advancement, lateral release, partial patellar ligament transposition and Galeazzi semitendinosus tenodesis was undertaken to stabilise the patella. The diagnostic criterion for ligamentous laxity was based on the Beighton scale. Outcomes were evaluated radiologically and functionally by measurement of the range of knee movement and isokinetic testing. The evaluation also included the Lysholm knee scale. Follow-up studies took place at a mean of 8.1 years (5 to 15) post-operatively. Normal patellar tracking without any recurrence of dislocation was obtained in ten out of 11 patients. Pain related to vigorous activity was reported by nine patients. Compared with the opposite normal side, the isokinetic tests revealed a statistically significant decrease in the maximal torque values for the affected quadriceps muscle (p = 0.003 and p = 0.004), but no difference between the knee flexors (for angular velocities of 60°/s and 180°/s) (p = 0.858 and p = 0.79). The applied surgical technique generally prevents the recurrence of the disorder in children with habitual patellar dislocation and ligamentous laxity. Quadriceps muscle weakness can be expected to occur post-operatively,. Cite this article: Bone Joint J 2015;96-B:129–33

Anterior cruciate ligament (ACL) injuries are among the most common and debilitating knee injuries in professional athletes with an incidence in females up to eight-times higher than their male counterparts. ACL injuries can be career-threatening and are associated with increased risk of developing knee osteoarthritis in future life. The increased risk of ACL injury in females has been attributed to various anatomical, developmental, neuromuscular, and hormonal factors. Anatomical and hormonal factors have been identified and investigated as significant contributors including osseous anatomy, ligament laxity, and hamstring muscular recruitment. Postural stability and impact absorption are associated with the stabilizing effort and stress on the ACL during sport activity, increasing the risk of noncontact pivot injury. Female patients have smaller diameter hamstring autografts than males, which may predispose to increased risk of re-rupture following ACL reconstruction and to an increased risk of chondral and meniscal injuries. The addition of an extra-articular tenodesis can reduce the risk of failure; therefore, it should routinely be considered in young elite athletes. Prevention programs target key aspects of training including plyometrics, strengthening, balance, endurance and stability, and neuromuscular training, reducing the risk of ACL injuries in female athletes by up to 90%. Sex disparities in access to training facilities may also play an important role in the risk of ACL injuries between males and females. Similarly, football boots, pitches quality, and football size and weight should be considered and tailored around females’ characteristics. Finally, high levels of personal and sport-related stress have been shown to increase the risk of ACL injury which may be related to alterations in attention and coordination, together with increased muscular tension, and compromise the return to sport after ACL injury. Further investigations are still necessary to better understand and address the risk factors involved in ACL injuries in female athletes. Cite this article: Bone Jt Open 2024;5(2):94–100

We review our results of arthroscopic capsular plication in patients with ligamentous laxity that had developed symptoms of instability after a traumatic event. Between 2004 and 2005, 115 patients with traumatic injury to their shoulder underwent arthroscopic stabilization and repair of their shoulder. Of these, twelve patients had ligamentous laxity and had their capsule plicated as a means to stabilize their shoulder. All had failed three months of biofeedback physiotherapy. The mean age of the patients was 29 years (range 17 to 46). The average time interval between date of injury and surgery was 21 months. They were reviewed retrospectively with a minimum follow up of 2 yeats. The functional outcome was assessed by Constant scoring system and Rowe score. At arthroscopy, capsular plication with a south to north direction would be fashioned with #1 PDS sutures. In multidirectional instability, the inferior and posterior capsule would be plicated as well. If the labrum was torn, this and the capsule would be repaired together. The repair was reinforced with rotator interval closure. Postoperatively the arm was rested in sling for four weeks followed by gradual mobilization. At a minimum follow up of two years, all twelve shoulders became stable. There were 8 excellent, 3 good and one fair result as graded by modified Rowe score. Re-arthroscopy in the patient with fair result showed good capsular repair and presence of scar tissue in the subacromial space. All patients rated their shoulder as normal. Ten patients returned to their preinjury level of competitive sport. Two patients returned to sport but at a lower level voluntarily. Arthroscopic capsular plication appears to be a safe and reliable technique in stabilizing shoulders in patients with ligamentous laxity. This form of repair should be offered to this group of patients if treatment with biofeedback physiotherapy fails

We evaluated the clinical outcome of arthroscopic labroplasty in 56 patients treated for shoulder instability owing to ligamentous laxity. In our technique, the antero-inferior labral capsular complex is detached and mobilised from the glenoid. It is advanced superiorly and plicated to create a new labrum, retensioning the capsule and decreasing the articular volume. Usually, a rotator interval plication is also added. Postoperatively, patients wear an adduction sling for three weeks, but movement is permitted within pain limits. The mean time to follow-up, when patients were clinically reviewed and assessed on the Walch-Du Play score, was 26 months (12 to 74). No intra-operative complications or nerve injuries were encountered. There was a single failure with frank redislocation. The mean Walch-Du Play score was 88/100 (10 to 100). Redundant capsule and a hypoplastic labrum are common in unstable shoulders owing to ligamentous laxity. The labroplasty creates a ‘bumper’ and addresses the excess of capsule. In our short-term experience, this arthroscopic technique is superior to the open capsular shift

Purpose: To determine whether generalized ligamentous laxity is a predisposing factor for primary traumatic anterior shoulder dislocation in young, active patients. Method: Prospective case series with age and sex matched controls. The Hospital Del Mar Criteria was utilized to measure generalized ligamentous laxity. Fifty-seven (n=57) consecutive individuals (age< 30) sustaining a primary traumatic anterior shoulder dislocation between 2003 and 2006 were examined for hyperlaxity. The control group was comprised of seventy-two (n=72) undergraduate university students without a prior history of shoulder dislocation or anterior cruciate ligament injury. Results: After adjusting for age and sex, the prevalence of hyperlaxity in the study group was 32.8% compared with 10.4% in the control group (p< 0.01). The prevalence of increased contralateral shoulder external rotation (> 85o) was 40.3% in the study group compared with 20.8% in the control group (p< 0.03). Among males, the prevalence of hyperlaxity was 28.3% in the study group and 5.3% in the controls (p< 0.01). Conclusion: Although several studies have looked at the variables affecting shoulder instability, generalized ligamentous laxity (as measured by validated criteria) has not previously been identified as a predisposing factor for primary traumatic shoulder dislocation. This study demonstrates that generalized joint laxity and increased external rotation in the contralateral shoulder were found to be more common in patients who had sustained a primary shoulder dislocation. These observations may suggest a role for shoulder-specific proprioceptive and strength training protocols in hyperlax individuals participating in high-risk sports. Furthermore, the implications of hyperlaxity on the surgical management of traumatic primary shoulder instability are uncertain

Introduction. While the use of stemmed implants is accepted for patients with medial ligament laxity in primary total knee arthroplasty (TKA), the role of stemmed implants in the setting of isolated lateral laxity is unclear. We present a cohort study to assess the effect of unstemmed, constrained TKA for isolated lateral laxity. Methods. 1745 primary TKA performed by the senior surgeon were reviewed. 39 knees in 33 patients with isolated lateral laxity managed with unstemmed components were compared to matched stemmed controls (37 knees in 28 patients). Lateral instability was defined intra-operatively based on >7mm gap in mid-flexion/full extension/figure-of-four with well-positioned components. Primary outcome measures were clinical failure for aseptic loosening (with need for revision as the endpoint) and any radiographic signs of loosening. Results. Average follow-up was 43 months for the unstemmed group (UG) and 25 months for the stemmed group (SG). UG and SG were matched for age, gender, BMI, arthritis etiology, and co-morbidities. The incidence of isolated lateral ligament laxity in this cohort was 4%. There was no difference in clinical outcomes between cohorts. There was no evidence of radiographic loosening; no revisions were performed for aseptic loosening in either group. One SG patient was revised for mid-flexion instability, while one UG patient had an isolated dislocation event without need for revision. Two patients in the UG were treated with incision/debridement and poly-exchange for acute infection. One patient in the SG underwent 2-stage reimplantation. Conclusion. From this data, a post/constraint can be used without stems to compensate for isolated lateral laxity. There is no significant increased risk of loosening with increased constraint, as lateral instability is primarily a swing-phase phenomenon. The goal is limiting varus thrust with improved gait kinematics and patient comfort. Further biomechanical testing and long-term clinical results are needed

The purposes of this study were to define the range of laxity of the interosseous ligaments in cadaveric wrists and to determine whether this correlated with age, the morphology of the lunate, the scapholunate (SL) gap or the SL angle. We evaluated 83 fresh-frozen cadaveric wrists and recorded the SL gap and SL angle. Standard arthroscopy of the wrist was then performed and the grades of laxity of the scapholunate interosseous ligament (SLIL) and the lunotriquetral interosseous ligament (LTIL) and the morphology of the lunate were recorded. Arthroscopic evaluation of the SLIL revealed four (5%) grade I specimens, 28 (34%) grade II, 40 (48%) grade III and 11 (13%) grade IV. Evaluation of the LTIL showed 17 (20%) grade I specimens, 40 (48%) grade II, 28 (30%) grade III and one (1%) grade IV.

On both bivariate and multivariate analysis, the grade of both the SLIL and LTIL increased with age, but decreased with female gender. The grades of SLIL or LTIL did not correlate with the morphology of the lunate, the SL gap or the SL angle. The physiological range of laxity at the SL and lunotriquetral joints is wider than originally described. The intercarpal ligaments demonstrate an age-related progression of laxity of the SL and lunotriquetral joints. There is no correlation between the grades of laxity of the SLIL or LTIL and the morphology of the lunate, the SL gap or the SL grade. Based on our results, we believe that the Geissler classification has a role in describing intercarpal laxity, but if used alone it cannot adequately diagnose pathological instability.

We suggest a modified classification with a mechanism that may distinguish physiological laxity from pathological instability.

Introduction: The relationship between the axial alignment of the knee and symptomatic instability of the collateral ligament is very important. This paper presents an approach to the management of chronic collateral ligament instability. Reconstruction of the MCL in the valgus knee and of the LCL in the varus knee is usually unsuccessful without re-alignment of the knee.

Method: The gait pattern of the patient with valgus alignment and MCL laxity demonstrates a medial thrust on weight-bearing. Laxity may involve the MCL alone, in combination with ACL laxity, or associated with LCL laxity. MCL laxity in the valgus knee is best managed with a varus distal femoral osteotomy. MCL laxity with medial osteoarthritis is best managed with an open wedge valgus tibial osteotomy.

LCL laxity in the varus knee responds well to valgus correction with a high tibial osteotomy. LCL laxity secondary to malunion of a lateral tibial plateau fracture can be managed with an open wedge varus high tibial osteotomy

Results: Fifty-two patients with chronic, symptomatic collateral ligament instability have been surgically reconstructed. Most cases involved multiple ligament injury and most were seen after the initial surgical procedure. Twenty-eight of 52 patients underwent two or more operative procedures before osteotomy. Twenty-one cases involved the MCL and 3l involved the LCL.

Varus distal femoral osteotomy was performed for isolated symptomatic MCL laxity. The average resultant anatomical axis was zero degrees. This resulted in loss of the medial thrust on weightbearing. Patients with injuries resulting in early medial OA with varus alignment and MCL laxity were treated with open wedge valgus high tibial osteotomy.

The majority of patients with LCL laxity and varus alignment responded to closing wedge valgus high tibial osteotomy. A smaller number (six) with depression of the lateral tibial plateau two degrees to fracture and associated LCL laxity responded to open wedge varus high tibial osteotomy.

ACL patients were followed for over two years (range two to four years) post-surgery. All patients were assessed clinically and radiographically. Clinical examinations included a Lysholm functional score and Tegner activity scale. Radiographic examination included pre- and post-operative three foot x-rays and pre-operation valgus, varus stem x-rays.

Gap balancing technique aims to achieve equal and symmetric gap at full extension and in flexion; however, little is known about the connection between the native and the replaced knee gaps. In this study, a novel robotic assisted ligament tensioning tool was used to measure the pre- and post- operative gaps to better understand their relationship when aiming for balance gaps in flexion and extension. The accuracy of a prediction algorithm for the post-operative gaps based on the native gap and implant alignment was evaluated in this study. The medial and lateral gap were smallest at full extension. The native gaps increase with flexion until 30 degrees where they plateaued for the remaining flexion range. The native lateral gap was larger than the medial gap throughout the flexion range. Planning for equal gaps at extension and flexion resulted with tightest gaps at these angle; however, the gaps in mid-flexion were 3–4 mm larger. Good agreement was observed between the post-operative results and the predicted gas from the software algorithm. The results showed that the native gaps are neither symmetric nor equal. In addition, aiming for equal gaps reduces the variation at these angles but could result in mid- flexion laxity. Advanced robotics-assisted instrumentation can aid in evaluation of soft-tissue and help in surgical planning of TKA. This allows the surgeon to achieve the targeted outcome as well as record the final implant tension to correlate with clinical outcomes.

Objectives

We performed in vitro validation of a non-invasive skin-mounted system that could allow quantification of anteroposterior (AP) laxity in the outpatient setting.

Conventional computer navigation systems using bone fixation have been validated in measuring anteroposterior (AP) translation of the tibia. Recent developments in non-invasive skin-mounted systems may allow quantification of AP laxity in the out-patient setting.

We tested cadaveric lower limbs (n=12) with a commercial image free navigation system using passive trackers secured by bone screws. We then tested a non-invasive fabric-strap system. The lower limb was secured at 10° intervals from 0° to 60° knee flexion and 100N of force applied perpendicular to the tibial tuberosity using a secured dynamometer. Repeatability coefficient was calculated both to reflect precision within each system, and demonstrate agreement between the two systems at each flexion interval. An acceptable repeatability coefficient of ≤3 mm was set based on diagnostic criteria for ACL insufficiency when using other mechanical devices to measure AP tibial translation.

Precision within the individual invasive and non-invasive systems measuring AP translation of the tibia was acceptable throughout the range of flexion tested (repeatability coefficient ≤1.6 mm). Agreement between the two systems was acceptable when measuring AP laxity between full extension and 40° knee flexion (repeatability coefficient ≤2.1 mm). Beyond 40° of flexion, agreement between the systems was unacceptable (repeatability coefficient >3 mm).

These results indicate that from full knee extension to 40° flexion, non-invasive navigation-based quantification of AP tibial translation is as accurate as the standard invasive system, particularly in the clinically and functionally important range of 20° to 30° knee flexion. This could be useful in diagnosis and post-operative follow-up of ACL pathology.

Conventional computer navigation systems using bone fixation have been validated in measuring anteroposterior (AP) translation of the tibia. Recent developments in non-invasive skin-mounted systems may allow quantification of AP laxity in the out-patient setting.

We tested cadaveric lower limbs (n=12) with a commercial image free navigation system using passive trackers secured by bone screws. We then tested a non-invasive fabric-strap system. The lower limb was secured at 10° intervals from 0° to 60° knee flexion and 100N of force applied perpendicular to the tibial tuberosity using a secured dynamometer. Repeatability coefficient was calculated both to reflect precision within each system, and demonstrate agreement between the two systems at each flexion interval. An acceptable repeatability coefficient of ≤3mm was set based on diagnostic criteria for ACL insufficiency when using other mechanical devices to measure AP tibial translation.

Precision within the individual invasive and non-invasive systems measuring AP translation of the tibia was acceptable throughout the range of flexion tested (repeatability coefficient ≤1.6mm). Agreement between the two systems was acceptable when measuring AP laxity between full extension and 40° knee flexion (repeatability coefficient ≤2.1mm). Beyond 40° of flexion, agreement between the systems was unacceptable (repeatability coefficient >3mm).

These results indicate that from full knee extension to 40° flexion, non-invasive navigation-based quantification of AP tibial translation is as accurate as the standard invasive system, particularly in the clinically and functionally important range of 20° to 30° knee flexion. This could be useful in diagnosis and post-operative follow-up of ACL pathology.

Conventional computer navigation systems using bone fixation have been validated in measuring anteroposterior (AP) translation of the tibia. Recent developments in non-invasive skin-mounted systems may allow quantification of AP laxity in the out-patient setting.

We tested cadaveric lower limbs (n=12) with a commercial image free navigation system using passive trackers secured by bone screws. We then tested a non-invasive fabric-strap system. The lower limb was secured at 10° intervals from 0° to 60° knee flexion and 100N of force applied perpendicular to the tibial tuberosity using a secured dynamometer. Repeatability coefficient was calculated both to reflect precision within each system, and demonstrate agreement between the two systems at each flexion interval. An acceptable repeatability coefficient of ≤3mm was set based on diagnostic criteria for ACL insufficiency when using other mechanical devices to measure AP tibial translation.

Precision within the individual invasive and non-invasive systems measuring AP translation of the tibia was acceptable throughout the range of flexion tested (repeatability coefficient ≤1.6 mm). Agreement between the two systems was acceptable when measuring AP laxity between full extension and 40° knee flexion (repeatability coefficient ≤2.1 mm). Beyond 40° of flexion, agreement between the systems was unacceptable (repeatability coefficient >3 mm).

These results indicate that from full knee extension to 40° flexion, non-invasive navigation-based quantification of AP tibial translation is as accurate as the standard invasive system, particularly in the clinically and functionally important range of 20° to 30° knee flexion. This could be useful in diagnosis and post-operative follow-up of ACL pathology.

We have shown in a previous study that patients with combined lesions of the anterior cruciate (ACL) and medial collateral ligaments (MCL) had similar anteroposterior (AP) but greater valgus laxity at 30° after reconstruction of the ACL when compared with patients who had undergone reconstruction of an isolated ACL injury. The present study investigated the same cohort of patients after a minimum of three years to evaluate whether the residual valgus laxity led to a poorer clinical outcome.

Each patient had undergone an arthroscopic double-bundle ACL reconstruction using a semitendinosus-gracilis graft. In the combined ACL/MCL injury group, the grade II medial collateral ligament injury was not treated. At follow-up, AP laxity was measured using a KT-2000 arthrometer, while valgus laxity was evaluated with Telos valgus stress radiographs and compared with the uninjured knee. We evaluated clinical outcome scores, muscle girth and time to return to activities for the two groups.

Valgus stress radiographs showed statistically significant greater mean medial joint opening in the reconstructed compared with the uninjured knees (1.7 mm (sd 0.9) versus 0.9 mm (sd 0.7), respectively, p = 0.013), while no statistically significant difference was found between the AP laxity and the other clinical parameters. Our results show that the residual valgus laxity does not affect AP laxity significantly at a minimum follow up of three years, suggesting that no additional surgical procedure is needed for the medial collateral ligament in combined lesions.

Introduction. Orthopedics is experiencing a significant transformation with the introduction of technologies such as robotics and apps. These, integrated into the post-operative rehabilitation process, promise to improve clinical outcomes, patient satisfaction, and the overall efficiency of the healthcare system. This study examines the impact of an app called Mymobility and intra-operative data collected via the ROSA® robotic system on the functional recovery of patients undergoing robot-assisted knee arthroplasty. Method. The study was conducted at a single center from 2020 to 2023. Data from 436 patients were included, divided into “active” patients (active users of Mymobility) and “non-active” patients. Clinical analyses and satisfaction surveys were carried out on active patients. The intra-operative parameters recorded by ROSA® were correlated with the Patient-Reported Outcome Measures (PROMs) collected via Mymobility. Result. Intra-operative data showed significant correlations with PROMs for the 48 active patients, highlighting the importance of parameters such as medial joint space and ligament laxity. No significant differences were observed between the sexes, but a positive correlation was detected between age and PROMs. The data analysis indicated that an increased medial joint space and reduced ligament laxity are associated with better PROMs. The adoption of Mymobility remained limited, with only 10% of patients fully utilizing the app. Critical factors have been identified to improve recruitment, engagement, and overall experience with the platform. Conclusion. The integration of technologies such as Mymobility and ROSA® in post-operative rehabilitation offers numerous advantages, including the objectification of data, active patient involvement, and personalized care. Challenges remain related to costs, patient compliance, and demographic limitations. Nevertheless, these technologies represent a milestone in modern peri-operative management, being able to improve clinical outcomes and the quality of care

Preoperative ligament laxity can be characterized intraoperatively using digital robotic tensioners. Understanding how preoperative knee joint laxity affects preoperative and early post-operative patient reported outcomes (PROMs) may aid surgeons in tailoring intra-operative balance and laxity to optimize outcomes for specific patients. This study aims to determine if preoperative ligament laxity is associated with PROMs, and if laxity thresholds impact PROMs during early post-operative recovery. 106 patients were retrospectively reviewed. BMI was 31±7kg/m. 2. Mean age was 67±8 years. 69% were female. Medial and lateral knee joint laxity was measured intraoperatively using a digital robotic ligament tensioning device after a preliminary tibial resection. Linear regressions between laxity and KOOS12-function were performed in extension (10°), midflexion (45°), and flexion (90°) at preoperative, 6-week, and 3-month time points. Patients were separated into two laxity groups: ≥7 mm laxity and <7 mm laxity. Student's t-tests determined significant differences between laxity groups for KOOS12-function scores at all time points. Correlations were found between preoperative KOOS12-function and medial laxity in midflexion (p<0.001) and flexion (p<0.01). Patients with <7 mm of medial laxity had greater preoperative KOOS12-function scores compared to patients with ≥7 mm of medial laxity in extension (46.8±18.2 vs. 29.5±15.6, p<0.05), midflexion (48.4±17.8 vs. 32±16.1, p<0.001), and flexion (47.7±18.3 vs. 32.6±14.7, p<0.01). No differences in KOOS12-function scores were observed between medial laxity groups at 6-weeks or 3-months. All knees had <5 mm of medial laxity postoperatively. No correlations were found between lateral laxity and KOOS12-function. Patients with preoperative medial laxity ≥7 mm had lower preoperative PROMs scores compared to patients with <7 mm of medial laxity. No differences in PROMs were observed between laxity groups at 6 weeks or 3 months. Patients with excessive preoperative joint laxity achieve similar PROMs scores to those without excessive laxity after undergoing gap balancing TKA