Knee Surgery Is Associated With Greater Odds of Knee Osteoarthritis Diagnosis.

CONTEXT: Knee osteoarthritis (OA) frequently develops following knee injury/surgery. It is accepted that knee injury/surgery precipitates OA with previous studies examining this link in terms of years after injury/surgery. However, postinjury OA prevalence has not been examined by decade of life; thereby, limiting our understanding of the age at which patients are diagnosed with posttraumatic knee OA. OBJECTIVE: Evaluate the association between the knee injury and/or surgical history, present age, and history of receiving a diagnosis of knee OA. DESIGN: Cross-sectional survey. SETTING: Online survey. PARTICIPANTS: A total of 3660 adults were recruited through ResearchMatch©. Of these, 1723 (47.1%) were included for analysis due to history of (1) knee surgery (SURG: n = 276; age = 53.8 [15.3] y; and body mass index [BMI] = 29.9 [8.0] kg/m2), (2) nonsurgical knee injury (INJ: n = 449; age = 46.0 [15.6] y; and BMI = 27.5 [6.9] kg/m2), or (3) no knee injury (CTRL: n = 998; age = 44.0 [25.2] y; and BMI = 26.9 [6.6] kg/m2). Respondents were subdivided by decade of life (20-29 through 70+). INTERVENTION: An electronic survey regarding knee injury history, treatment, and diagnosis of knee OA. MAIN OUTCOME MEASURES: Binary logistic regression determined the association between knee surgical status and OA by decade of life. Participants with no histories of OA or lower-extremity injury were the referent categories. BMI was a covariate in all analyses. RESULTS: SURG respondents were more likely to report having knee OA than CTRL for all age groups (odds ratios: 11.43-53.03; P < .001). INJ respondents aged 30 years and older were more likely to have OA than CTRL (odds ratios: 2.99-14.22; P < .04). BMI influenced associations for respondents in their 50s (P = .001) and 60s (P < .001) only. CONCLUSIONS: INJ increased the odds of reporting a physician diagnosis of knee OA in adults as young as 30 to 39 years. Importantly, SURG yielded 3 to 4 times greater odds of being diagnosed with knee OA compared with INJ in adults as young as 20 to 29 years. Delaying disease onset in these young adults is imperative to optimize the quality of life long term after surgery.

Evaluation of Agreement Between Participant and Expert on Jump-Landing Characteristics During a 4-Week Intervention.

CONTEXT: Feedback is an important factor in interventions designed to reduce anterior cruciate ligament injury risk. Self-analysis feedback requires participants to self-critique their jump-landing mechanics; however, it is unknown if individuals can effectively self-analyze their own biomechanics and if this self-analysis agrees with observed biomechanical changes by an expert. OBJECTIVE: To determine agreement between an expert and participants on biomechanical errors committed during 3 of 12 sessions, which were part of an intervention to change jump-landing biomechanics in healthy females. DESIGN: Descriptive analysis. SETTING: Research laboratory. PATIENTS OR OTHER PARTICIPANTS: Healthy recreationally active females with no history of lower-extremity fracture or surgery. INTERVENTIONS: Participants completed a 4-week, 12-session feedback intervention. Each intervention session lasted approximately 15 minutes and included asking participants to perform 6 sets of 6 jumps off a 30-cm-high box placed 50% of their height away from the target landing area. Participants performed self-analysis feedback and received expert feedback on 7 different jump-landing criteria following each set of jumps. MAIN OUTCOME MEASURES: Data were coded, and agreement between the expert and the participant was assessed using Cohen's unweighted kappa for sessions 1, 6, and 12. RESULTS: There was agreement between the expert and participants for 0/7 criteria for session 1, 3/7 criteria for session 6, and 4/7 criteria for session 12. CONCLUSIONS: Participants demonstrated some agreement with the expert when evaluating their jump-landing biomechanics. Self-analysis feedback may not replace what an expert can provide; both types of feedback may be better used in conjunction to produce significant biomechanical changes. Changes made by the participant may not translate into biomechanical changes during a real-life game or practice situation. Future research should continue to investigate effective interventions to reduce injury risk.

Knee Frontal-Plane Biomechanics in Adults With or Without Bone Marrow Edema-Like Lesions After Anterior Cruciate Ligament Injury.

CONTEXT: Lateral subchondral bone bruises (BBs) occur frequently with anterior cruciate ligament (ACL) injuries. These BBs are associated with pain during weight bearing, leading individuals to increase medial tibiofemoral loading to alleviate pain laterally. Increased medial tibiofemoral loading may precipitate the development or progression of posttraumatic osteoarthritis; however, no in vivo biomechanical data exist to confirm that lateral BBs increase medial tibiofemoral loading as measured by the external knee-adduction moment (KAM). OBJECTIVE: To determine whether lateral BBs after ACL injury increase the external KAM during walking. DESIGN: Descriptive laboratory study. SETTING: University research laboratory. PATIENTS OR OTHER PARTICIPANTS: Eleven volunteers with an ACL injury (age = 20.36 ± 4.03 years, height = 177.60 ± 8.59 cm, mass = 79.70 ± 16.33 kg), 12 with an ACL injury and a lateral BB (ACL + BB; age = 19.25 ± 5.58 years, height = 170.71 ± 9.40 cm, mass = 66.79 ± 11.91 kg), and 12 healthy controls (age = 19.67 ± 5.19 years, height = 173.29 ± 11.58 cm, mass = 67.07 ± 11.25 kg) participated. INTERVENTION(S): We recorded peak KAM during 3 walking trials (1.1 ± 0.6 m/s) in which participants walked over a force platform located in the field of view of a motion-capture system. MAIN OUTCOME MEASURE(S): Peak KAM was calculated during the first half of stance using standard inverse-dynamics analysis, averaged across trials, and examined via 1-way analysis of variance. Knee pain and function were determined from the International Knee Documentation Committee Subjective Knee Evaluation Form and compared among groups via the Kruskal-Wallis test. RESULTS: Peak KAM did not differ among groups (ACL injury = 0.14 ± 0.07 Nm·kg-1·m-1, ACL + BB = 0.21 ± 0.08 Nm·kg-1·m-1, control = 0.20 ± 0.08 Nm·kg-1·m-1; F2,35 = 3.243, P = .052). Knee-pain frequency and severity were greater in the ACL-injury (frequency = 2.55 ± 1.81, severity = 3.36 ± 1.75; both P < .001) and ACL + BB (frequency = 3.58 ± 2.81, severity = 4.08 ± 3.20; both P < .001) groups than in the control group (frequency = 0.00 ± 0.00, severity = 0.00 ± 0.00). Knee function was greater in the control group (100.00 ± 0.00) than in the ACL-injury (59.35 ± 17.31; P < .001) and ACL + BB (46.46 ± 25.85; P < .001) groups. CONCLUSIONS: The ACL + BB groups did not walk with a greater external KAM than the ACL-injury or control groups. Thus, lateral tibiofemoral BB did not influence knee frontal-plane loading after ACL injury.

Longitudinal Evaluation of Stair Walking Biomechanics in Patients with ACL Injury.

PURPOSE: After anterior cruciate ligament (ACL) injury and reconstruction, abnormal biomechanics during daily tasks may have prominent and detrimental long-term consequences on knee joint health. The purpose of this study was to longitudinally evaluate hip and knee joint biomechanics during stair ascent and descent in patients with acute ACL injury and at return to activity after ACL reconstruction. METHODS: Twenty individuals with unilateral ACL injury (age, 20.9 ± 4.4 yr; height, 172.4 ± 7.5 cm; mass, 76.2 ± 12.2 kg) that were scheduled to undergo surgical reconstruction were compared with 20 healthy matched controls (age, 21.7 ± 3.7 yr; height, 173.7 ± 9.9 cm; mass, 76.1 ± 19.7 kg). Lower extremity biomechanics were recorded using three-dimensional motion analysis during stair ascent and descent at two testing sessions (before surgery and at approximately 6 months after surgery or when they were allowed to return to unrestricted physical activity). Time between sessions for healthy participants was matched on the basis of the ACL group. Peak sagittal and frontal plane knee and hip joint angles and moments, joint angles at initial contact, and joint excursions across stance phase were evaluated. RESULTS: The ACL-injured limb of patients experienced smaller knee extension moments than the uninjured limb and healthy controls during stair ascent and descent (P < 0.05) before and 6 months after ACL reconstruction. During stair ascent, ACL patients experienced more extended knee joint positions and less sagittal plane knee joint excursions, coupled with greater frontal plane hip joint excursions (P < 0.05). CONCLUSIONS: Patients with ACL injury experience reductions in knee flexion angle and knee extension moments during stair walking. These alterations were observed both before and after reconstruction, suggesting that early gait retraining interventions may be beneficial in these patients.

Quadriceps/hamstrings co-activation increases early after total knee arthroplasty.

UNLABELLED: Quadriceps and hamstrings weakness and co-activation are present following total knee arthroplasty (TKA) and may impair functional performance. How surgery and post-operative rehabilitation influence muscle activation during walking early after surgery is unclear. PURPOSE: Examine muscle strength and activation during walking before and one and 6-months post-TKA. METHODS: Ten patients (n=6 female; age: 64.7 ± 7.9 years; body mass index[BMI]:29.2 ± 2.5 kg/m(2)) and 10 healthy adults (n=6 female; age: 60.6 ± 7.4 years; BMI: 25.5 ± 4.0 kg/m(2)) participated. The patients underwent bilateral quadriceps and hamstrings strength testing and assessment of quadriceps/hamstrings co-activation and on/off timing using surface electromyography during a six-minute walk test (6MW). Groups, limbs, and changes with TKA surgery were compared. RESULTS: Patients reported greater 6MW knee pain pre- versus post-TKA and compared to controls (P<0.05). Patients had weaker surgical limb hamstrings (P<0.05) and bilateral quadriceps (P<0.05) strength than controls pre- and post-TKA. Before and 1-month post-TKA, patients had side-to-side differences in quadriceps and hamstrings strength (P<0.05). Controls walked farther than patients (P<0.01). Patients demonstrated greater surgical limb co-activation pre-operatively than controls (P<0.05). Co-activation was higher bilaterally one-month post-TKA compared to controls (P<0.05). Patients turned off their quadriceps later during stance than controls before and 1-month post-TKA (P<0.05). CONCLUSIONS: Muscle strength, co-activation, and timing differed between patients and controls before and early after surgery. Rehabilitation to improve strength and muscle activation seems imperative to restore proper muscle firing patterns early after surgery.

Muscle strength and functional recovery during the first year after THA.

BACKGROUND: Patients undergoing total hip arthroplasty (THA) often are satisfied with the decrease in pain and improvement in function they achieve after surgery. Even so, strength and functional performance deficits persist after recovery, but these remain poorly characterized; knowledge about any ongoing strength or functional deficits may allow therapists to design rehabilitation programs to optimize recovery after THA. QUESTIONS/PURPOSES: The purposes of this study were to (1) evaluate postoperative muscle strength, function, and quality of life during the first year after THA; and (2) compare strength and function in patients 1 year after THA with a cohort of healthy peers. METHODS: Twenty-six patients undergoing THA were assessed 1, 3, 6, and 12 months postoperatively, and 19 adults with no hip pathology were tested as a control group. Isometric muscle strength (hip flexors, extensors, abductors, knee extensors, and flexors), functional performance (stair climbing, five times sit-to-stand, timed-up-and-go, 6-minute walk, and single-limb stance tests), and self-reported function (Hip Disability and Osteoarthritis Score, SF-36, and UCLA activity score) were compared. RESULTS: One month after THA, patients had 15% less hip flexor and extensor torque, 26% less abductor torque, 14% less knee extensor and flexor torque, and worse performance on the stair climbing, timed-up-and-go, single-limb stance, and 6-minute walk. Compared with healthy adults, patients 12 months after THA had 17% less knee extensor and 23% less knee flexor torque; however, the functional testing (including stair climbing, five times sit-to-stand, and the 6-minute walk) showed no significant differences with the patient numbers available between individuals undergoing THA and healthy control subjects. SF-36 Physical Component Scores, although significantly improved from preoperative levels, were significantly worse than healthy adults 1 year after THA (p < 0.01). CONCLUSIONS: Patients experience early postoperative strength losses and decreased functional capacity after THA, yet strength deficits may persist after recovery. This may suggest that rehabilitation may be most effective in the first month after surgery.

Importance of attenuating quadriceps activation deficits after total knee arthroplasty.

Total knee arthroplasty (TKA) is associated with persistent quadriceps dysfunction. Because quadriceps dysfunction impairs functional performance, minimizing quadriceps dysfunction by attenuating central activation deficits early after surgery may improve function later in life. Rehabilitation strategies incorporating neuromuscular electrical stimulation and early, aggressive quadriceps strengthening may prove beneficial. Furthermore, surgical approaches, such as minimally invasive TKA, may minimize postoperative quadriceps dysfunction.

Maximizing quadriceps strength after ACL reconstruction.

The primary objectives of ACL surgery and rehabilitation are to restore knee function to preinjury levels and promote long-term joint health. Often these goals are not achieved, however. The quadriceps is critical to dynamic joint stability, and weakness of this muscle group is related to poor functional outcomes. Because of this, identifying strategies to minimize quadriceps weakness following ACL injury and reconstruction is of great clinical interest. This article reviews the current literature and critically discusses current rehabilitation approaches to restore quadriceps muscle function after ACL reconstruction.