1.4 Common MSK Conditions & Management
Key Takeaways
- Rotator cuff tears most often involve the supraspinatus; post-repair rehab progresses PROM -> AAROM/isometrics -> dynamic strengthening over months
- ACL reconstruction uses criterion-based progression: restore full extension early, build quad symmetry, return to sport at ~9-12 months after passing hop tests
- Total hip arthroplasty precautions depend on approach: posterior avoids flexion >90, adduction past midline, and internal rotation; anterior avoids extension and external rotation
- Total knee arthroplasty goals target ~0-90 deg by 2 weeks and ~0-120 deg by 6 weeks, emphasizing quad activation and gait
- Low back pain management is active: McKenzie directional preference, centralization as a good prognostic sign, core stabilization, and graded activity
- Adhesive capsulitis follows freezing, frozen, and thawing stages; the shoulder capsular pattern is external rotation > abduction > internal rotation most limited
- Lateral epicondylitis (tennis elbow) affects the common extensor origin and responds to eccentric wrist-extension loading
- Fracture healing stages are inflammation, soft callus, hard callus, and remodeling
Common Musculoskeletal Conditions & Management
The NPTE tests identification, evaluation, and treatment of the orthopedic conditions PTs see most. This section covers the highest-yield ones along with their precautions and evidence-based progressions.
Rotator Cuff Pathology
The rotator cuff (SITS) dynamically stabilizes the glenohumeral joint:
| Muscle | Action | Nerve |
|---|---|---|
| Supraspinatus | Initiates abduction (first ~15-30 deg) | Suprascapular (C5-C6) |
| Infraspinatus | External rotation | Suprascapular (C5-C6) |
| Teres minor | External rotation | Axillary (C5-C6) |
| Subscapularis | Internal rotation | Subscapular (C5-C6) |
The supraspinatus tears most often, in its relatively avascular zone near the greater-tuberosity insertion. Post-repair rehab is staged: Phase I (0-6 wk) protect the repair with sling, pendulums, and PROM within limits; Phase II (6-12 wk) restore AROM and begin isometrics; Phase III (12-16 wk) progressive isotonic cuff and scapular work; Phase IV (16-24+ wk) sport/work-specific training. Pushing active elevation too early risks re-tear.
ACL Reconstruction
Reconstruction (bone-patellar-tendon-bone or hamstring autograft) follows a criterion-based progression rather than the calendar:
| Phase | Goals | Criteria to advance |
|---|---|---|
| Acute (0-2 wk) | Control swelling, restore full extension, quad activation | Full passive extension, active quad set |
| Early (2-6 wk) | Full extension, start CKC | 0 deg extension, minimal effusion |
| Mid (6-12 wk) | Strengthen, begin running | ~90% quad symmetry, no effusion |
| Late (3-6 mo) | Agility, plyometrics | Hop tests >90% of uninvolved |
| Return to sport (9-12 mo) | Full return | Pass functional + psychological readiness |
Restoring full knee extension early is the single most important goal — a flexion contracture causes lasting gait and patellofemoral problems. Early CKC quadriceps loading is preferred because it limits anterior tibial shear on the graft.
Joint Replacement Precautions
Total Hip Arthroplasty (THA)
Precautions depend on the surgical approach:
- Posterior (posterolateral) approach — most common. To prevent posterior dislocation, avoid hip flexion beyond 90 degrees, adduction past midline (no crossing the legs), and internal rotation. Teach a raised toilet seat, no low chairs, and an abduction pillow in bed.
- Anterior (direct anterior) approach. To prevent anterior dislocation, avoid hip extension beyond neutral, external rotation, and the combined extension-plus-external-rotation position. Precautions are generally less restrictive and lifted earlier.
Total Knee Arthroplasty (TKA)
Functional ROM goals target roughly 0-90 degrees by 2 weeks and 0-120 degrees by 6 weeks. Priorities are quadriceps (especially VMO) activation, full active extension, edema control, and progressive gait training. A persistent extension lag predicts long-term gait deviation.
Low Back Pain, Capsulitis, Tendinopathy, and Fracture Healing
Low back pain management is active. In the McKenzie (MDT) system, a derangement changes with repeated motions and is treated by the directional preference (commonly extension); centralization — symptoms retreating from distal toward the spine — is a favorable prognostic sign and confirms the treatment direction. Core/lumbar stabilization and graded return to activity follow.
Adhesive capsulitis (frozen shoulder) moves through freezing (painful, 2-9 mo), frozen (stiff, 4-12 mo), and thawing (recovery, 5-24 mo). The shoulder capsular pattern is external rotation most limited > abduction > internal rotation. Treat with mobilization (grades III-IV in the frozen phase), stretching, and pain control.
Lateral epicondylitis (tennis elbow) is a tendinopathy of the common extensor origin (especially ECRB); eccentric wrist-extension loading is the evidence-based core, with a counterforce brace as an adjunct. Medial epicondylitis (golfer's elbow) affects the common flexor origin.
Fracture healing proceeds through inflammation (~1-7 days, hematoma), soft callus (~2-3 weeks), hard callus (~3-12 weeks, bony bridging), and remodeling (months to years). PT respects weight-bearing orders and avoids loading that disrupts early callus.
Red Flags and the Differential Mindset
Beyond the specific protocols, the NPTE tests whether you can recognize when an 'orthopedic' presentation is actually something that needs referral. Red flags that should prompt physician contact rather than continued PT include unexplained weight loss, night pain unrelieved by position change, a history of cancer, fever/chills with back pain (possible infection), saddle anesthesia with bowel/bladder change (cauda equina), and progressive neurological deficit. Recognizing these protects the patient and is a recurring 'what should the PT do first/next' answer.
Frequently Confused Pairs
Several condition pairs are deliberately contrasted on the exam. Lateral vs. medial epicondylitis: lateral involves the wrist extensors (ECRB) and responds to eccentric extension loading, while medial involves the flexor-pronator group. Posterior vs. anterior THA precautions: posterior limits flexion/adduction/internal rotation; anterior limits extension/external rotation—reversing them is a classic distractor. ACL vs. PCL tests: Lachman/anterior drawer for the ACL, posterior drawer for the PCL. **Capsular vs.
non-capsular limitation**: a proportional multi-plane loss suggests arthritis or capsulitis, whereas a single-plane mechanical block suggests a loose body or meniscus. Anchoring on the one distinguishing feature—rather than the overlapping symptoms—turns these into reliable points.
Post-Operative Communication and Protocols
For surgical cases, the exam expects you to respect the surgeon's protocol and weight-bearing orders and to recognize that protocols are criterion- and tissue-healing-driven. When a question pits 'advance aggressively' against 'honor the precaution,' the precaution wins unless the patient has met the stated criteria. Knowing the standard ROM and weight-bearing milestones (such as TKA targets and THA precautions) lets you identify both when a patient is behind expected progress and when a proposed activity violates a precaution—two of the most common post-operative item types.
A patient is 2 days after a POSTERIOR-approach total hip arthroplasty. Which position should be AVOIDED?
Which rotator cuff muscle is MOST commonly torn?
In McKenzie classification, centralization of low back symptoms indicates:
What is the capsular pattern of the glenohumeral joint?
Which are precautions after a POSTERIOR-approach total hip arthroplasty? (Select all that apply)
Select all that apply
Lateral epicondylitis (tennis elbow) is best managed with: