Weekly MSK Literature Review

Monday: ACL Recovery Trajectories and PROM Sensitivity

Main Points

• Systematic review of 84 RCTs mapping natural recovery after ACL rupture showed IKDC scores improve steeply from baseline to 12 months (SMC 2.0 at 3 months, 2.2 at 6 months, 2.2 at 12 months) then plateau with minimal gains to 24 months (SMC 2.3).

• KOOS subscales for pain, symptoms, and ADL recovered rapidly by 6 months and plateaued, while sport and quality of life domains showed slower recovery but still plateaued by 12 months.

• Both operative and nonoperative management groups demonstrated similar trajectory shapes, suggesting recovery patterns reflect natural healing and adaptation more than treatment modality.

• PROMs demonstrated strong sensitivity for early recovery (0-12 months) but limited responsiveness beyond 12 months, despite athletes typically returning to sport during this later period.

• Recovery trajectories were consistent across different PROMs (IKDC, KOOS, ACL-QOL, Lysholm, Tegner, CKRS), with IKDC showing superior responsiveness compared to KOOS or Lysholm scales.

Clinical Significance

This evidence fundamentally challenges how we use PROMs for return-to-sport decision-making and late-stage rehabilitation monitoring. The plateau at 12 months suggests that subjective measures may not capture functional readiness, neuromuscular control, or sport-specific capacity during the critical 12-24 month window when clearance decisions are made. Clinicians should set realistic expectations about recovery timelines and supplement PROMs with objective functional testing for clearance decisions.

Citation

Ridha, A., Raj, S., Searle, H., Ahmed, I., Smith, N., Metcalfe, A., & Khatri, C. (2025). The recovery trajectory of anterior cruciate ligament ruptures in randomised controlled trials: A systematic review and meta-analysis of operative and nonoperative treatments. Knee Surgery, Sports Traumatology, Arthroscopy, 33, 3781–3793. https://doi.org/10.1002/ksa.12626

Tuesday: ACL Reconstruction Timing: Early vs Delayed Surgery

Main Points

• Meta-analysis of 11 RCTs (972 participants) found no meaningful differences between early and delayed ACL reconstruction for range of motion, knee laxity, operative time, retear rates, infection rates, Tegner activity scores, or KOOS subscales at any follow-up point from 6 months to 5 years.

• Small, statistically significant improvements favored early surgery for IKDC scores at 6 months (mean difference +2.8 points) and Lysholm scores at 1-2 years (mean difference +2.6-3.0 points), but these fell below minimal clinically important difference thresholds.

• Definitions of “early” ranged from 8 days to 10 weeks post-injury, while “delayed” ranged from 4 weeks to over 3 months, yet findings remained robust across subgroup analyses despite this heterogeneity.

• All delayed-surgery protocols emphasized structured prehabilitation focused on a full range of motion, quadriceps activation, and strength restoration, which likely mitigated risks of postoperative stiffness and arthrofibrosis.

• Graft selection was similar across timing groups (83% hamstring, 10% BPTB, 6% other), eliminating this as a confounding variable.

Clinical Significance

This evidence liberates patients and clinicians from the pressure of urgent surgical scheduling and elevates prehabilitation to a cornerstone of ACL care. The lack of outcome differences, combined with the potential reduction in arthrofibrosis risk when surgery is delayed until full ROM and strength are restored, supports a shared decision-making model where patient readiness, not arbitrary timelines, drives surgical timing. This has major implications for care pathways, insurance authorization processes, and patient anxiety management.

Citation

Shen, X., Liu, T., Xu, S., Chen, B., Tang, X., Xiao, J., & Qin, Y. (2022). Optimal timing of anterior cruciate ligament reconstruction in patients with anterior cruciate ligament tear: A systematic review and meta-analysis. JAMA Network Open, 5(11), e2242742. https://doi.org/10.1001/jamanetworkopen.2022.42742

Wednesday: Standardizing Clinical Performance Assessment in Physical Therapy Education

Main Points

• Global physical therapy education lacks standardized clinical performance assessment despite decades of development, with countries like the US, Canada, UK, Ireland, and Australia having national frameworks, while many regions, including the Philippines, rely on institution-specific instruments.

• Fragmented assessment creates inequitable evaluations, inconsistent expectations across clinical sites, limited benchmarking capacity, variable graduate competence, and challenges with international mobility and employer confidence.

• Authors argue standardization is an ethical obligation tied to patient safety and public trust, emphasizing it should define what is assessed and how judgments are made while preserving local flexibility for cases, settings, and practice contexts.

• A pragmatic national framework should include core competency maps aligned to entry-level domains, workplace-based assessments (Mini-CEX, DOPS, multisource feedback), standardized checkpoints (OSCEs, EPA assessments), shared rubrics using entrustment scales like TRUST-PT, rater training with calibration, moderation processes for borderline cases, and digital infrastructure that avoids vendor lock-in.

• The new CBEPT framework from APTA (2025) provides 19 Entrustable Professional Activities, 8 domains, and 54 competencies that offer a ready blueprint for competency-based assessment implementation.

Clinical Significance

This editorial addresses a foundational quality issue in physical therapy workforce development with direct implications for patient safety, professional credibility, and health system trust. Standardized assessment reduces the “placement lottery” where student evaluation depends more on site culture than actual competence, supports equity by reducing subjective bias, and enables data-driven program improvement. For healthcare systems and payers, this represents a critical infrastructure investment in workforce quality assurance and risk mitigation.

Citation

Vitente, A. C., Rafael, C. L., & Lazaro, R. T. (2025). Standardizing assessment of clinical performance in physical therapy: From good intentions to shared standards. Philippine Journal of Physical Therapy, 4(3), 1–5. https://doi.org/10.46409/002.QUJZ9284

Thursday: Persistent Quadriceps Weakness After ACL Reconstruction

Main Points

• Systematic review with longitudinal meta-analysis of 232 studies (34,220 participants) revealed quadriceps strength at 1 year post-ACLR reaches only 85% of contralateral limb and 80% of uninjured controls, representing 15-20% persistent deficits.

• Strength recovery follows a non-linear trajectory with rapid improvement in the first 3-6 months, continued but slowing gains to 12-18 months, then minimal improvement beyond 1.5 years, even out to 5-9 years post-surgery.

• At 5 years post-ACLR, quadriceps strength remained at only 91% of the contralateral limb with no meaningful recovery occurring after the 12-18 month window, challenging assumptions about long-term normalization.

• Limb symmetry indices (LSI) systematically underestimate true strength deficits because the contralateral “uninjured” limb is often also weaker than normative controls, with between-person comparisons showing larger deficits than within-person symmetry measures.

• Hamstring deficits were smaller but still present at 5-7% at 1 year for concentric strength, with isometric hamstring strength showing larger deficits exceeding 10%.

Clinical Significance

This evidence exposes a critical gap between current rehabilitation approaches and actual outcomes, despite decades of protocol refinement; meaningful quadriceps weakness persists as an unsolved problem. The early plateau at 12-18 months suggests either inadequate rehabilitation intensity, poor adherence, biological constraints, or fundamental flaws in intervention design. For clinicians, this demands reconsideration of discharge criteria (LSI alone is insufficient), extended rehabilitation timelines, and novel intervention strategies. For researchers and payers, this represents a clear quality gap requiring investment in implementation science and innovative treatment approaches.

Citation

Girdwood, M., Culvenor, A. G., Rio, E. K., Patterson, B. E., Haberfield, M., Couch, J., Mentiplay, B., Hedger, M., & Crossley, K. M. (2025). Tale of quadriceps and hamstring muscle strength after ACL reconstruction: A systematic review with longitudinal and multivariate meta-analysis. British Journal of Sports Medicine, 59, 423–434.

Friday: Physical Therapy as Core Treatment for Osteoarthritis

Main Points

• Osteoarthritis is a complex whole-organ disease driven by interacting mechanical, metabolic, inflammatory, and genetic factors, including abnormal loading, obesity, diabetes, dyslipidemia, gut microbiota dysbiosis, genetic variants (GDF5, COMP, CHADL, COL11A1), sex differences, and aging-related low-grade inflammation.

• Physical therapy is consistently recommended as first-line intervention by major guidelines (OARSI, ACR, EULAR) because it is safe, low-cost, accessible, and addresses multiple disease pathways, including cartilage-subchondral bone health, systemic inflammation, gut microbiota composition, metabolic health, periarticular muscle strength, neuromuscular control, and pain sensitivity.

• Effective PT modalities include aerobic exercise (walking, cycling, swimming, Tai Chi, yoga), resistance training targeting quadriceps, hip abductors, and posterior chain, neuromuscular training for balance and proprioception, and adjunctive therapies like acupuncture and low-intensity pulsed ultrasound, with combined approaches superior to single modalities.

• Preclinical evidence shows treadmill and wheel running reduce pain and protect bone/cartilage, exercise mitigates metabolic OA in obesity and diabetes models, and swimming reduces chondrocyte apoptosis and inflammatory cytokines, though excessive or high-impact loading can worsen OA.

• Despite strong evidence, PT remains underutilized due to a lack of standardized protocols for intensity, frequency, and duration, variability in clinical practice, limited understanding of optimal dosing, inconsistent patient adherence, and poor integration with metabolic and lifestyle interventions.

Clinical Significance

This review repositions physical therapy from a symptom-management strategy to a disease-modifying intervention that addresses root pathophysiology through multiple biological mechanisms. The contrast with pharmacologic approaches, which have failed to demonstrate disease modification despite decades of investment, elevates PT to essential infrastructure for OA care. However, implementation gaps remain the critical barrier. For health systems, this demands investment in standardized protocols, clinician training on progressive exercise prescription, integration with weight management and metabolic optimization programs, and payment models that support adequate dosing and long-term adherence.

Citation

Wang, W., Niu, Y., & Jia, Q. (2022). Physical therapy as a promising treatment for osteoarthritis: A narrative review. Frontiers in Physiology, 13, 1011407. https://doi.org/10.3389/fphys.2022.1011407

Weekly Themes & Strategic Insights

1. Recovery Trajectories Follow Predictable Patterns That Challenge Current Practice Paradigms

Recovery after both ACL injury and osteoarthritis follows non-linear trajectories that plateau earlier than commonly assumed. Ridha demonstrated IKDC scores plateau by 12 months post-ACL injury, while Girdwood showed quadriceps strength plateaus by 12-18 months with minimal improvement to 5 years. These convergent timelines suggest current rehabilitation approaches may be inadequate in intensity, duration, or mechanistic targeting, fundamentally challenging discharge criteria and return-to-sport clearance protocols that assume continued improvement.

2. Measurement Tools: Shape Limit, Clinical Decision-Making

Multiple papers revealed critical gaps between what we measure and what matters clinically. Ridha showed PROMs capture early recovery but lack sensitivity for late-stage functional readiness during the critical return-to-sport window. Girdwood demonstrated that LSI systematically underestimates true strength deficits by comparing to a contralateral limb that is also compromised. Vitente argued that fragmented assessment creates inequitable evaluations and inconsistent competence. The pattern is clear: measurement standardization and validity issues represent system-level quality threats across education, clinical practice, and research.

3. Timing Matters Less Than Quality of Intervention and Patient Preparation

Shen’s meta-analysis showed that surgical timing (early vs delayed ACL reconstruction) produced no meaningful outcome differences when delayed groups received structured prehabilitation. This finding parallels Wang’s emphasis on exercise quality, dosing, and adherence as more important than specific modalities for OA. Girdwood’s persistent strength deficits despite protocol refinement further suggest implementation quality, not just protocol design, drives outcomes. The strategic implication is clear: investing in intervention quality, patient preparation, and adherence support yields greater returns than optimizing timing or adding new treatment options.

4. Biological and Mechanical Factors Create Persistent Deficits. Current Approaches Cannot Resolve

Girdwood’s finding of persistent 15-20% quadriceps deficits at 1 year and minimal recovery beyond 18 months despite decades of rehabilitation research represents a fundamental unsolved problem. Wang’s description of OA as a complex multi-system disease with mechanical, metabolic, inflammatory, and genetic drivers reinforces that single-modality interventions are insufficient. Both papers point to the need for novel mechanistic approaches, better implementation strategies, and acceptance that some deficits may represent biological constraints rather than rehabilitation failures.

5. Standardization Enables Quality, Equity, and Continuous Improvement

Vitente made the explicit case that standardized clinical assessment is an ethical obligation tied to patient safety and professional credibility. This theme extends across the week’s literature: Ridha’s trajectory data enable better expectation-setting, Shen’s timing evidence supports protocol standardization, Girdwood’s strength benchmarks reveal quality gaps, and Wang’s call for standardized PT protocols addresses implementation barriers. Without shared frameworks for assessment, protocols, and outcome measurement, the field cannot achieve equitable care, valid benchmarking, or systematic quality improvement.

6. Physical Therapy Addresses Root Pathophysiology, Not Just Symptoms

Wang’s review positioned PT as a disease-modifying intervention for OA through multiple biological mechanisms, including cartilage protection, inflammation reduction, metabolic optimization, and neuromuscular enhancement. This mechanistic foundation, rather than symptomatic relief, elevates PT to essential infrastructure. Girdwood’s demonstration of persistent strength deficits and Ridha’s plateau in subjective outcomes suggest current PT approaches may be inadequately dosed or mechanistically targeted, but the biological rationale for PT as core treatment remains strong. The strategic imperative is optimizing dosing, adherence, and integration with metabolic interventions rather than questioning PT’s central role.

Implications for MSK Care Delivery, Technology, and Strategy

Measurement Infrastructure: Healthcare systems must invest in standardized, validated outcome measurement that extends beyond PROMs to include objective functional testing, strength benchmarking against normative controls rather than contralateral limbs, and competency-based assessment frameworks for clinician performance.

Rehabilitation Dosing and Duration: Current rehabilitation timelines and intensity may be fundamentally inadequate given persistent strength deficits for 5 years and PROM plateaus by 12 months. Care pathways should extend supervised rehabilitation beyond typical 3-6 month windows, increase loading intensity earlier, and implement long-term monitoring with booster interventions.

Prehabilitation as Standard of Care: Evidence showing no disadvantage to delayed ACL surgery when prehabilitation restores ROM and strength, combined with OA evidence emphasizing exercise quality over modality, positions prehabilitation as a high-value intervention that reduces surgical urgency, improves patient preparation, and potentially reduces complications. Payment models and care pathways should incentivize comprehensive prehabilitation.

Clinical Decision Support Tools: Technology platforms should integrate recovery trajectory benchmarks, normative strength data, and standardized competency frameworks to guide clinical decision-making, reduce practice variation, flag patients deviating from expected recovery curves, and support evidence-based return-to-sport clearance rather than relying solely on time-based or LSI criteria.

Implementation Science Investment: The gap between evidence (PT as disease-modifying OA treatment, structured prehabilitation enabling delayed surgery) and practice (PT underutilization, fragmented protocols, persistent strength deficits) represents an implementation failure. Systems should invest in clinician training on progressive exercise prescription, patient adherence support, standardized protocol adoption, and quality monitoring infrastructure.

Alternative Payment Models: Current fee-for-service models inadequately support extended rehabilitation timelines, comprehensive prehabilitation, or the higher-intensity interventions needed to address persistent deficits. Value-based arrangements should reward functional outcomes, strength restoration to normative benchmarks, and adherence to evidence-based protocols rather than visit volume.

Workforce Development: Vitente’s call for standardized clinical assessment frameworks represents critical infrastructure for quality assurance. Academic programs, credentialing bodies, and health systems should collaborate on shared competency maps, entrustment-based assessment, rater training, and digital platforms that enable benchmarking and continuous improvement while preserving local contextual flexibility.

Bottom Line

This week’s literature reveals that MSK care has strong mechanistic foundations but persistent implementation gaps: we know PT works through multiple biological pathways, we understand recovery trajectories plateau earlier than assumed, and we recognize that intervention quality matters more than timing, yet fragmented assessment, inadequate dosing, poor measurement tools, and weak adherence support prevent us from achieving the outcomes the evidence suggests are possible. The strategic imperative is shifting investment from new treatment discovery to implementation infrastructure, measurement standardization, and delivery model redesign.

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