A 45-year-old male sustained a traumatic work-related patellar tendon rupture from the inferior pole of the patella while exiting a vehicle. The patient had a past medical history of diabetes mellitus type II. The patient was evaluated within 22 days of his injury and initially treated with primary repair 81 days after the injury. The tendon was repaired with two number 2 nonabsorbable sutures in a Krackow suture configuration throughout the length of the patellar tendon and anchored through bone tunnels in the patella. This patellar height was corrected to an Insall-Salvati Index (ISI) and Caton-Deschamps Index (CDI) of 1.23 and 1.14 (Figure 1) from 1.4 and 1.34, respectively (Figure 2). His knee was immobilized in a locking brace for two weeks, and then physical therapy was initiated for range of motion at two weeks postoperatively. The patient progressed slowly through physical therapy gaining 100 degrees of active leg flexion but developed significant quadriceps atrophy, patella alta, and 10 degrees of an extensor lag at 7 months following the procedure. The patient was compliant with the standard rehabilitation protocol and had no history of traumatic reinjury. Eleven months after the primary procedure, the patient was referred to our clinic for persistent pain, pain with squatting and kneeling, instability, and stagnation in functional recovery which prevented him from returning to work up to this point. Subjectively, he reported a 4/10 pain level at rest. Clinical examination revealed proximal migration of the patella, 2+ coarse patellar crepitus, full active range of motion, 3+/5 quadriceps strength, and a 10-degree lag with single leg raise. T2-weighted MRI and lateral knee radiograph at 11-month follow-up confirmed patella alta deformity (CDI = 1.51, ISI = 1.55), an intact albeit lax patellar tendon, and cartilage fissuring near the inferior patellar apex (Figure 3). There was no additional ligamentous injury noted on MRI. His preoperative patient-reported outcome scores can be found in Table 1. A collective decision was made with the patient at this time to proceed with revision patellar tendon repair with the goal of returning to work at some capacity and resuming his normal activities of daily living.
The previous midline incision was dissected to visualize and confirm obvious redundancy and thinning of the patellar tendon. A 2 x 4 x 1 cm rectangular block of redundant patellar tendon tissue was outlined and resected to correct the degree of patella alta. The patella was mobilized using blunt dissection. The suture material from the index repair was removed, and the distal patellar footprint was prepared. Two 2.5 PEEK corkscrew anchors (Arthrex, Naples, FL) were anchored 2 cm apart on the distal patellar footprint. Krackow sutures were passed through the midsubstance of the patellar tendon, and with the opposite limb of each stitch, a half hitch was made such that a pulley mechanism was created (Figure 4). The tendon was reapproximated, and final fixation was secured with four mattress anchor knots with five alternating half hitches. The knee was brought to 30 degrees of flexion and the construct was stable. The wound was closed with a standard layered closure. Postoperative lateral knee radiograph displayed a CDI of 1.09 and an ISI of 1.16 (Figure 5), which confirmed that patella alta had been corrected. At 18-month follow-up, the patient had a repeat MRI performed which demonstrated a CDI of 1.35 (Figure 6).
Following the operation, a locked extension brace was applied for full-time use, and he began physical therapy two weeks postoperatively. The patient was compliant with his rehabilitation protocol and did not suffer any setbacks in the postoperative period. At his 1-year follow-up examination, the patient did not appear in acute distress, had no joint effusion, did not have patellar apprehension, demonstrated a nonantalgic gait, showed full active range of motion with no lag (Figure 7), displayed a negative Clarke exam, and had 4/5 quadriceps strength. In addition, the patient had 5 mm of anterior translation bilaterally on KT-1000 arthrometry testing and 20.6 pounds of force on maximal muscle testing of leg extension on the right compared to 21.3 pounds on the left as measured by a handheld dynamometer. The patient reported a pain level of 2/10 with activity, which was a decrease from his preoperative pain level (4/10). He reported occasional use of Tylenol for pain. His PRO scores at 1-year follow-up can be found in Table 1. Despite a relatively benign physical exam (Figure 7) and subjective reporting of satisfaction with the revision procedure and his outcome, the patient reported moderate functional limitations. Permanent work-duty restrictions were subsequently outlined as a functional capacity examination, and patient reported outcomes did not permit return to his full occupational capacity.