Objective To elucidate whether and how injection site diversity influences on the sodium hyaluronate (HA) distribution on cartilage surface of the knee joint.Methods From September 2014 to December 2014, 32 human cadaveric knees were sorted from small to large based on femoral condyle width (FCW) and divided into group Ⅰ (n=16, odd number, the patella medial approach) and group Ⅱ (n=16, even number, injected through the medial joint line approach).Knees of both groups were interfused with a 5％ (mg: ml) methylene blue tracer.Each specimen was then simulated a 5°-45° alternating walking for 2 h in the Electro Force platform.Afterwards, all the knee cavities were cut open to examine the range of HA distribution.Based on the eight-zoning classification law for the knee cartilage surface, the coverage area of HA in each zone was scored and the characteristics of HA distribution was depicted, as well as HA zonal distribution diversity between groups were statistically analyzed.Results HA of both patella medial and medial joint line subgroups showed analogical distribution in all zones except the lateral tibial plateau at the time of FCW ≤ 7.0 cm.However, HA coverage through the patella medial approach showed significantly higher distribution scores in the patella zone and the femoral trochlear zone, but significant lower distribution scores in the antero-lateral/postero-lateral femoral condyle, the medial posterior femoral condyle zone and the lateral tibial plateau zone compared with medial joint line approach at the time of FCW ＞ 7.0 cm.Conclusion When delivered through different injection approaches, HA showed analogical distribution characteristics in most zones of the knee cavity in population with a small bodily shape (FCW ≤ 7.0cm), but significant diverse distribution characteristics in population with a big bodily shape (FCW ＞7.0 cm).When FCW ＞ 7.0cm, HA injected through the medial-patellar approach tended to be distributed mainly over the patella-femoral articulation and the anterior knee cavity, while HA injected through the joint line approach tended to be distributed mainly over the tibio-femoral articulation and the posterior knee cavity.

OBJECTIVE: To assess the therapeutic effect of hyaluronate acid (HA) injection through the subpatellar route for treatment of chondromalacia patellae (CP). METHODS: Eighty-eight patients with the diagnosis of CP were enrolled in this prospective study, including 38 with early CP (CP group) and 50 with advanced CP (patellofemoral arthritis group) diagnosed based on image presentations. All the patients received intra-articular HA injections through a subpatellar route once a week for 5 consecutive weeks. The primary outcome measures included WOMAC index scores and Lequesne scores before and at 4, 12, 26 and 52 weeks after the injections. The secondary outcome measures included the 30-m walking time and stair ascending and descending time (one floor) before and at 1, 2, 3, and 4 weeks after the injections. RESULTS: In both groups the patients showed significantly decreased WOMAC scores and Lequesne scores at 4, 12, 26 and 52 weeks after HA injections as compared with the baseline scores (all < 0.01). No significant difference was found between the two groups in WOMAC scores and Lequesne scores at 4 or 12 weeks after the injections (both >0.05). The WOMAC scores and Lequesne scores at 26 and 52 weeks after the injections were significantly higher in patellofemoral arthritis group than in CP group (both < 0.05). In both groups, the 30-m walking time and the stair ascending and descending time decreased significantly at 1, 2, 3, and 4 weeks after HA injections (all < 0.05) without significant differences between the two groups (all >0.05). CONCLUSIONS HA injection through the subpatellar route is effective for treatment of CP. HA injection produces better long-term efficacy for treatment of early CP than for advanced CP where patellofemoral arthritis occurs.
Chondromalacia Patellae ; Follow-Up Studies ; Humans ; Hyaluronic Acid ; Injections, Intra-Articular ; Osteoarthritis, Knee ; Pain Measurement ; Prospective Studies ; Severity of Illness Index ; Treatment Outcome