Treatment of inferior pole fracture of the patella with tension-free external immobilization

Abstract

Background Inferior pole fracture of the patella (IPFP) has small and comminuted fracture blocks that are hard to immobilize, and early mobilization may lead to loss of fracture reduction and immobilization failure. Therefore, a difficulty of treatment is to achieve rigid immobilization with early functional exercise. Here, a new treatment method of tension-free external immobilization is put forward. Methods The clinical data of 11 IPFP patients treated with tension-free external immobilization from May 2016 to June 2019 were retrospectively analyzed. There were six males and five females aged 39.0 ± 12.8 years (range 18–53 years). IPFP was caused by traffic accidents in five cases and falls in six cases. All cases had unilateral closed injuries, including four in the left knee and seven in the right knee. The preoperative range of motion of the knee was 22.0 ± 7.5° (10–30°). The time from injury to operation was 4.5 ± 1.3 d (3–7 d). The operation-related indices were recorded, and the function of the affected knee was assessed by the Böstman score. Results All operations were successful. The operation time was 56.4 ± 8.4 mi (45–70 min), the intraoperative blood loss was 54.1 ± 14.6 mL (40–80 mL), and the length of hospital stay was 7.5 ± 1.9 d (5–11 d). The mean follow-up time was 20.4 ± 7.6 months (12–36 months), the duration of fracture healing was 8.9 ± 1.5 weeks (7–12 weeks), and the removal time of the external immobilization device was 10.4 ± 0.9 weeks (9–12 weeks). At the last follow-up, the range of motion had no significant difference between the affected knee (129.7 ± 3.3°, range 125–135°) and the unaffected knee (130.8 ± 3.8°, range 126–137°) (t = 0.718, p < 0.05). The Böstman score of the knee was 29.2 ± 1.0 points (27–30 points), including 10 excellent cases (90.9%) and one good case (9.1%). Conclusion Tension-free external immobilization is a feasible treatment for IPFP. It can help with early functional exercise and achieve a satisfactory clinical effect.

Surgical treatment of inferior pole fractures of the patella: a systematic review

“…These devices combined rigid fixation devices (e.g., interosseous K‐wire) and tensile fixation devices (e.g., figure‐8 wire). Extra‐patella devices included those fixing the patella to the tibia with a patellotibial wire ( n = 86, 4 studies) [21, 22, 37, 46] or external skeletal fixators (ESF, n = 11, 1 study) [36]. Although cerclage wire ( Fig.…”

Candy box technique for the fixation of inferior pole patellar fractures: finite element analysis and biomechanical experiments

“…Due to their small size and concentrated stress, it is difficult to maintain effective reduction and strong fixation, which makes their treatment challenging [ 4 ]. The methods reported in the literature have advantages and disadvantages, as well as various complications [ 1 ]. How to minimize complications while ensuring sufficient internal fixation strength and simultaneously meeting the early functional exercise needs of the knee joint remains an unresolved issue.…”

“…The inferior pole of the patella refers to the cancellous bone in the portion of the lower 1/4 of the patella that is not covered by articular cartilage [ 1 , 2 ]. Fractures of the inferior pole of the patella are thus extra-articular fractures and account for approximately 9.3–22.4% of patellar fractures [ 3 – 6 ].…”

“…The patella is an important component of the knee extensor system, and inferior pole patellar fractures disrupt the integrity and continuity of this system, as well as the normal anatomical and biomechanical relationships of the patellofemoral joint [ 8 ]. Therefore, the correct treatment of these fractures is essential for restoring stability, integrity, and function of the knee extensor system [ 1 , 9 ].…”