What is the typical resolution time for locking and catching of the knee with a posterior meniscal tear?

Resolution Time for Locking and Catching with Posterior Meniscal Tear

The provided evidence does not contain specific data on resolution timeframes for locking and catching symptoms with posterior meniscal tears, but based on available evidence, true mechanical locking typically requires surgical intervention for resolution, while pseudo-locking from degenerative tears often improves with conservative management over 3-6 months.

Understanding the Clinical Context

The term "locked knee" requires careful distinction between true mechanical locking (inability to achieve full extension) versus pseudo-locking symptoms (catching, clicking, intermittent locking) 1. True mechanical locking represents an orthopaedic emergency requiring prompt diagnosis and treatment 1.

Key Diagnostic Considerations

• MRI can change management from surgical to conservative in up to 48% of patients presenting with a locked knee, which traditionally would be considered an indication for arthroscopic procedure 2
• MRI has 96% sensitivity and 97% specificity for detecting meniscal tears when correlated with arthroscopy 2
• The most frequent causes of a locked knee are meniscal tear, ACL rupture, or loose bodies 1

Resolution Timeframes Based on Management Approach

Conservative Management (Degenerative Tears)

For patients with degenerative meniscal tears and mechanical symptoms:

• Most patients experience important improvement in pain and function without arthroscopy 2
• In less than 15% of participants, arthroscopic surgery resulted in small improvement at 3 months, but this benefit was not sustained at 1 year 2
• APM led to greater resolution of intermittent locking (70% vs 46%) and clicking (41% vs 25%) compared to physical therapy at 6 months 3
• However, the presence of meniscal symptoms (including locking and catching) did not modify pain improvement between surgical versus conservative treatment 3

Surgical Management

• Recovery from arthroscopic surgery typically takes 2-6 weeks 2
• At least 1-2 weeks off work is required, depending on recovery speed and physical demands 2

Critical Clinical Pitfalls

The major caveat is that degenerative knee disease explicitly excludes patients with persistent objective locked knee 2. This distinction is crucial:

• Persistent objective locked knee requires different management than intermittent mechanical symptoms 2
• Patients over 35 years with clicking, catching, or intermittent locking (but NOT persistent objective locking) fall under degenerative knee disease 2
• For true mechanical locking with inability to extend, arthroscopy remains the gold standard for management 1

Evidence-Based Recommendation Algorithm

For posterior meniscal tears with locking/catching symptoms:

1. Determine if true mechanical locking exists (fixed flexion, block to complete extension) 1

   • If YES → Arthroscopy indicated; symptoms resolve within 2-6 weeks post-operatively 2
   • If NO (intermittent symptoms only) → Proceed to step 2

2. For intermittent locking/catching in patients >35 years:

   • Conservative management is recommended (exercise therapy, injections) 2
   • Expected timeline: 3-6 months for symptom improvement based on trial data 2, 3
   • 46% resolution of intermittent locking with physical therapy at 6 months 3

3. MRI should be obtained to guide management decisions, as it can change up to 48% of locked knee cases from surgical to conservative 2

The evidence strongly suggests that while surgical intervention may provide faster resolution of mechanical symptoms (70% vs 46% for locking at 6 months), this does not translate to meaningful differences in pain or functional outcomes 3, making conservative management the preferred initial approach for most cases without true mechanical locking 2.