KNEE INJURY - JAZZ/THEATRICAL DANCE

Abstract

HISTORY 17 y/o female theatrical/jazz dancer presented to a sports medicine clinic two months after sustaining her fifth left patellar dislocation in a two-year span. She was doing well five months prior, when she had this most recent dislocation that occurred while she was standing still doing an upper body dance routine. Her patella was reduced in the ER with normal post reduction films. She left the ER with a patellar cut-out brace w/o lateral buttress and no instructions on proper use/weaning. She was started on a very basic strengthening program that included only quad extension sets, isometric quad sets and lunges. She felt that the knee was unstable and had significant retro-patellar pain that precluded almost all activity. Other significant medical problems included HTN and recently diagnosed sponge kidney disease. PHYSICAL EXAMINATION Significant atrophy noted w/in entire left quadriceps group. There was a five-centimeter difference in thigh circumference when compared to the right. The calf on the left was 1.5 cm smaller as compared to the right. ROM of the left knee revealed 30–35 degrees of hyperextension & 70–75 degrees of flexion. There was a smaller degree of genu recurvatum noticed on the right. There was tightness at her end limit of left knee flexion along the anterior inferior patella. Increased laxity in the left patella as compared to the right. Slight medial joint line tenderness. No notable effusion or erythema of the knee. No laxity of the ACL, PCL, MCL, or LCL was noted. MMT was significant for left hip flexors 4+-5/5, left knee extensors 3–3+/5, left ankle dorsiflexors 4+/5, and left hamstrings 4/5. The left EHL, EDL, & all muscle groups tested in the right lower extremity were 5/5 strength. Pinprick in L1 to S2 dermatomes and in all peripheral nerve distributions was intact and symmetrical bilaterally. Reflexes were a brisk 3+ at the left patella, ankle, and internal hamstrings. DIFFERENTIAL DIAGNOSIS Status post Left patellar dislocation & persistent patellofemoral pain. Disuse atrophy. Left femoral nerve injury. Left lumbrosacral plexopathy. Left L4 radiculopathy R/O meniscal tear. R/O ACL tear R/O osteochondritis Dissecans. TEST AND RESULTS MRI Left thigh (9 days post injury): Large knee joint effusion. Medial patellar & lateral femoral bone contusions. Complete tear of medial retinaculum. Abnormal placement of lateral meniscus with a tear at lateral joint line & possible meniscal cyst inferior to lateral meniscus displacement. MRI Left thigh, STIR sequencing (4 months post injury): Abnormal signal within vastus medialis, lateralis and intermedius musculature w/o evidence of fatty atrophy. No abnormality within neurovascular bundle. Septate uterus. EMG/NCS left lower extremity (2 months post injury): Normal saphenous sensory response. Needle EMG - Abnormal spontaneous activity in vastus medialis (fibs and PSWs) & vastus lateralis (PSWs) with normal motor units. Normal exam of iliopsoas, tibialis anterior, adductor longus, & medial gastrocnemius muscles. EMG left lower extremity (6 months post injury): Needle EMG — Few polyphasics & reduced recruitment pattern seen in left vastus lateralis & rectus femoris. FINAL WORKING DIAGNOSIS Left patellar dislocation. Acute femoral neuropathy distal to inguinal ligament & saphenous sensory branch d/t patellar dislocation. Sponge kidney disease (no apparent impact on patellofemoral pathology). TREATMENT AND OUTCOMES Patellar buttress brace. McConnell taping. Quadriceps strengthening exercises: VMO >VL strengthening. Adductor, hip flexor, & TFL strengthening. Slow quadriceps & TFL stretching to increases knee flexion. Gait mechanics training to reduce genu recurvatum (focus on reverse origin-activation of gastrocnemius & eccentric activation of hamstrings). Proprioceptive & balance training Complete abstinence from the use of e-stim & U/S. Patient referred to orthopedic surgeons to evaluate for possible realignment if no femoral recovery and/or recurrent dislocations. Continued persistent atrophy, but slowly advancing ADLs & social activities. Await progress after activity increases.