Autologous chondrocyte implantation (ACI) has demonstrated good clinical success in the repair of articular cartilage defects in the knee. Postoperative rehabilitation after ACI is considered critical in returning the patient to an optimal level of function by attempting to create the appropriate mechanical environment for cartilage regrowth, and it involves a progressive program that emphasizes full motion, progressive partial weight bearing (PWB), and controlled exercises. While evidence-based research is clearly lacking in all components of ACI rehabilitation, one important element in this treatment algorithm that has been subjected to some early scientific study is the gradual progression of the patient back to full weight-bearing (WB) gait after surgery. With the continual advancement of ACI surgical techniques, along with clinical experience and improved knowledge of histology and of the maturation process of chondrocytes, proposed postoperative WB protocols have evolved to better reflect the nature of the specific ACI surgery. The purpose of this article is to present the varied PWB programs that have been practiced alongside the evolving ACI surgical technique, the experimental basis for such protocols, the issues pertinent to the accurate prescription of WB, and future directions for developing such methods to best return patients to an optimal level of function after ACI.
Jay R. Ebert and Peter K. Edwards
Jay R. Ebert, Anne Smith, Peter K. Edwards and Timothy R. Ackland
Matrix-induced autologous chondrocyte implantation (MACI) is an established technique for the repair of knee chondral defects. Despite the reported clinical improvement in knee pain and symptoms, little is known on the recovery of knee strength and its return to an appropriate level compared with the unaffected limb.
To investigate the progression of isokinetic knee strength and limb symmetry after MACI.
Private functional rehabilitation facility.
58 patients treated with MACI for full-thickness cartilage defects to the femoral condyles.
MACI and a standardized rehabilitation protocol.
Main Outcome Measures:
Preoperatively and at 1, 2, and 5 y postsurgery, patients underwent a 3-repetition-maximum straight-leg raise test, as well as assessment of isokinetic knee-flexor and -extensor torque and hamstring:quadriceps (H:Q) ratios. Correlation analysis investigated the association between strength and pain, demographics, defect, and surgery characteristics. Linear-regression analysis estimated differences in strength measures between the operated and nonoperated limbs, as well as Limb Symmetry Indexes (LSI) over time.
Peak knee-extension torque improved significantly over time for both limbs but was significantly lower on the operated limb preoperatively and at 1, 2, and 5 y. Mean LSIs of 77.0%, 83.0%, and 86.5% were observed at 1, 2, and 5 y, respectively, while 53.4–72.4% of patients demonstrated an LSI ≤ 90% across the postoperative timeline. Peak knee-flexion torque was significantly lower on the operated limb preoperatively and at 1 year. H:Q ratios were significantly higher on the operated limb at all time points.
While peak knee-flexion and hip-flexor strength were within normal limits, the majority of patients in this study still demonstrated an LSI for peak knee-extensor strength ≤ 90%, even at 5 y. It is unknown how this prolonged knee-extensor deficit may affect long-term graft outcome and risk of reinjury after return to activity.
Jennifer S. Howard, Jay R. Ebert and Karen Hambly
Peter K. Edwards, Jay R. Ebert, Gregory C. Janes, David Wood, Michael Fallon and Timothy Ackland
Matrix-induced autologous chondrocyte implantation (MACI) has become an established technique for the repair of chondral defects in the knee. MACI has traditionally required an open arthrotomy, but now lends itself to an arthroscopic technique, which may decrease the associated comorbidity of arthrotomy, potentially allowing for faster rehabilitation.
To compare postoperative outcomes between arthroscopic and open arthrotomy techniques of MACI and present a case for faster recovery and accelerated rehabilitation after surgery.
Retrospective cohort study.
Private functional rehabilitation facility.
78 patients (41 arthroscopic, 37 open) treated with MACI for full-thickness cartilage defects to the femoral condyles.
According to surgeon preference, patients recruited over the same time period underwent MACI performed arthroscopically or via a conventional open arthrotomy. Both surgical groups were subjected to an identical rehabilitation protocol.
Main Outcome Measures:
Patient-reported (Knee Injury and Osteoarthritis Outcome Score, Short Form Health Survey, and visual analogue scale) and functional (6-min-walk test, 3-repetition straight-leg-raise test [3R-SLR]) outcomes were compared presurgery and at 3, 6, and 12 mo postsurgery. Active knee range of motion (ROM) was additionally assessed 4 and 8 wk postsurgery. MRI evaluation was assessed using magnetic-resonance observation of cartilage-repair tissue (MOCART) scores at 3 and 12 mo. The length of hospital stay was evaluated, while postsurgery complications were documented.
Significant improvements (P < .05) for both groups were observed over the 12-mo period for patient-reported and functional outcomes; however, the arthroscopic cohort performed significantly better (P < .05) in active knee-flexion and -extension ROM and the 3R-SLR. No differences were observed in MOCART scores between the 2 groups at 12 mo. Patients who received arthroscopic implantation required a significantly reduced (P < .001) hospital stay and experienced fewer postoperative complications.
Arthroscopic MACI in combination with “best practice” rehabilitation has shown encouraging early results, with good clinical outcomes to 12 mo, reduced length of patient hospitalization, and reduced risk of postsurgery complications. This may have important implications for postoperative rehabilitation and a faster return to full function.
Jay R. Ebert, Peter K. Edwards, Daniel P. Fick and Gregory C. Janes
Gluteus medius rehabilitation is of critical importance given its role in pelvic and lower limb stability, and the known link between gluteus medius weakness and many lower limb conditions.
To systematically review the literature and present an evidence-based graduated series of exercises to progressively load gluteus medius.
A systematic literature search was conducted in January 2016 to identify studies reporting gluteus medius muscle activity as a percentage of maximal volitional isometric contraction (MVIC), during rehabilitation exercises. Studies that investigated injury free participants were included. No restrictions were placed on the type or mode of exercise, though exercises that could not be accurately replicated or performed within an independent setting were excluded. Studies that did not normalize electromyographic activity to a side lying MVIC were excluded. Exercises were stratified based on exercise type and %MVIC: low (0% to 20%), moderate (21% to 40%), high (41% to 60%), and very high (> 61%).
20 studies were included in this review, reporting outcomes in 33 exercises (and a range of variations of the same exercise). Prone, quadruped, and bilateral bridge exercises generally produced low or moderate load. Specific hip abduction/rotation exercises were reported as moderate, high, or very high load. Unilateral stance exercises in the presence of contralateral limb movement were often high or very high load activities, while high variability existed across a range of functional weight-bearing exercises.
This review outlined a series of exercises commonly employed in a rehabilitation setting, stratified based on exercise type and the magnitude of gluteus medius muscular activation. This will assist clinicians in tailoring gluteus medius loading regimens to patients, from the early postoperative through to later stages of rehabilitation.
Jay R. Ebert, Kate E. Webster, Peter K. Edwards, Brendan K. Joss, Peter D’Alessandro, Greg Janes and Peter Annear
Context: The importance of rehabilitation and evaluation prior to return to sport (RTS) in patients undergoing anterior cruciate ligament reconstruction has been reported. Objective: This study sought to investigate current perspectives of Australian orthopedic surgeons on rehabilitation and RTS evaluation. Design: Survey. Participants: Members of the Australian Knee Society. Main Outcome Measures: A 14-question survey was disseminated to Australian Knee Society members (orthopedic surgeons) to investigate (1) preferred graft choice, (2) estimated retear rate, (3) importance of preoperative and postoperative rehabilitation, and (4) preferred timing of RTS and evaluation prior to RTS discharge. Results: Of all 85 Australian Knee Society members contacted, 86% (n = 73) responded. Overall, 66 respondents (90.4%) preferentially used hamstring tendon autografts. All surgeons estimated their retear rate to be ≤15%, with 31 (42.5%) <5%. Twenty-eight surgeons (38.4%) reported no benefit in preoperative rehabilitation. The majority of surgeons (82.2%–94.5%) reported that postoperative rehabilitation was important within various periods throughout the postoperative timeline. Most surgeons did not permit RTS until ≥9 months (n = 56, 76.7%), with 17 (23.3%) allowing RTS between 6 and 9 months. The most highly reported considerations for RTS clearance were time (90.4%), functional capacity (90.4%), and strength (78.1%). Most commonly, knee strength and/or function was assessed via referral to a preferred rehabilitation specialist (50.7%) or with the surgeon at their practice (11.0%). Conclusions: This survey revealed variation in beliefs and practices surrounding rehabilitation and RTS evaluation. This is despite the current evidence demonstrating the benefit of preoperative and postoperative rehabilitation, as well as the emerging potential of RTS assessments consisting of strength and functional measures to reduce reinjury rates.