Application of three-dimensional-printed porous tantalum cones in total knee arthroplasty revision to reconstruct bone defects.

Purpose: Three-dimensional (3D) printing technology has emerged as a new treatment method due to its precision and personalization. This study aims to explore the application of a 3D-printed personalized porous tantalum cone for reconstructing the bone defect in total knee arthroplasty (TKA) revision. Methods: Between November 2017 and October 2020, six patients underwent bone reconstruction using 3D-printed porous tantalum cones in TKA revision. The knee function was assessed using the Hospital for Special Surgery (HSS) score pre- and postoperatively. The pain was measured by the visual analog scale (VAS) pre- and postoperatively. The quality of life was measured using the 36-Item Short Form Health Survey (SF-36) to pre- and postoperatively evaluate the relief of pain. Operation time, intraoperative blood loss, postoperative drainage volume, and complications were also recorded. At the last follow-up, all patients received X-ray and computed tomography (CT) to confirm the effect of bone reconstruction. Results: After an average follow-up duration of 26.3 months, no patients developed any operation-related complications. The average intraoperative blood loss and postoperative drainage volumes were 250.1 ± 76.4 ml and 506.7 ± 300.8 ml, respectively. At the last follow-up, the HSS score was significantly higher than that before operation, indicating that the knee function was significantly improved (p < 0.001). During the follow-up, the mean VAS score decreased and the mean SF-36 score increased, both of which were significantly improved compared with preoperative conditions (p < 0.001). Radiological examination at the final follow-up showed that cones implanted into the joint were stable and bone defects were effectively reconstructed. Conclusion: This study demonstrated that 3D-printed porous tantalum cones could effectively reconstruct bone defects and offer anatomical support in TKA revision. Further studies are still needed to confirm the long-term effect of 3D-printed tantalum cones for reconstructing bone defects.

Altered spontaneous calcium signaling of in situ chondrocytes in human osteoarthritic cartilage.

Intracellular calcium ([Ca2+]i) signaling is an essential universal secondary messenger in articular chondrocytes. However, little is known about its spatiotemporal features in the context of osteoarthritis (OA). Herein, by examining the cartilage samples collected from patients undergoing knee arthroscopic surgery, we investigated the spatiotemporal features of spontaneous [Ca2+]i signaling in in situ chondrocytes at different OA stages. Our data showed zonal dependent spontaneous [Ca2+]i signaling in healthy cartilage samples under 4 mM calcium environment. This signal was significantly attenuated in healthy cartilage samples but increased in early-degenerated cartilage when cultured in 0 mM calcium environment. No significant difference was found in [Ca2+]i intensity oscillation in chondrocytes located in middle zones among ICRS 1-3 samples under both 4 and 0 mM calcium environments. However, the correlation was found in deep zone chondrocytes incubated in 4 mM calcium environment. In addition, increased protein abundance of Cav3.3 T-type voltage dependent calcium channel and Nfatc2 activity were observed in early-degenerated cartilage samples. The present study exhibited OA severity dependent spatiotemporal features of spontaneous [Ca2+]i oscillations of in situ chondrocytes, which might reflect the zonal specific role of chondrocytes during OA progression and provide new insight in articular cartilage degradation during OA progression.

An Arthroscopic Second-Look Study on the Effect of Remnant Preservation on Synovialization of Bone-Patellar Tendon-Bone Allograft in Anterior Cruciate Ligament Reconstruction.

PURPOSE: To assess the effects of preserved more anterior cruciate ligament (ACL) remnant on synovial coverage, knee stability, and function after bone patellar-tendon-bone (BPTB) allograft reconstruction through second-look arthroscopy and follow-up study. METHODS: From June 2007 to February 2009, 51 patients received single bundle BPTB allograft ACL reconstruction and second arthroscopic examination. The patients were divided into 4 types according to the types of ACL remnant: type 1, 18 had bridging between the posterior cruciate ligament and the tibia; type 2, 21 had bridging between the intercondylar notch roof and the tibia; type 3, 4 had bridging between the lateral condyle and the tibia; and type 4, 8 subjects had no ACL remnants. Clinical results were evaluated with the KT-1000 maximum displacement test and Lysholm scale at mean 12.3- and 53.5-month follow-up. Second-look synovium coverage was recorded as follows: covering 25% or less, 25% to 50%, 50% to 75%, and more than 75%. RESULTS: Mean percentage of synovium coverage, Lysholm scale, and KT-1000 side-to-side difference were poorer in types 3 and 4 than the other 2 types at mean 12.3-month follow-up without statistical differences. The result of the final follow-up was comparable with the first one. Four patients had ruptured grafts and accepted revision surgery. Three of them belonged to types 3 and 4, and 1 patient with sport trauma belonged to type 2. There were other 11 patients with different types of impingement and partial absorption of grafts. CONCLUSIONS: Although lack of statistical power, follow-up study and second-look arthroscopy showed that preserved type 3 and 4 ACL remnant caused poorer synovium coverage and might lead to earlier failure when using BPTB allograft. Early minor laxity at 12.3-month follow-up seemed to be not progressive at the final follow-up. LEVEL OF EVIDENCE: Level III, case-control study.

[Autograft of femoral head for acetabular reconstruction in total hip arthroplasty for developmental dysplasia of the hip with complicated deformity].

OBJECTIVE: To observe autograft of femoral head for acetabular reconstruction in total hip arthroplasty(THA)without shortening femoral osteotomy for developmental dysplasia of the hip (DDH) with complicated deformity. METHODS: A case series of 18 Crowe type-III-IV DDH patients (19 hips) with osteoarthritis between December 2004 and October 2010 was reported. There were 2 male and 16 female patients. Mean age was 34.3 years (19-44 years) and limb shortening 4.5 cm (3.0-6.2 cm), and preoperative Harris score was 40 ± 17. All cases were accomplished through posterolateral approach by the same surgeon and underwent the procedure of acetabular reconstruction using a bulk femoral head autograft and periarticular soft tissue releases(dissection of the entire articular capsule, scar tissues and osteophytes), but had no procedure of shortening by subtrochanteric transverse osteotomy. Design data through paired t-test compared the preoperative and postoperative Harris scores, also the radiographic observation, in order to asses the clinical efficacy of acetabular reconstruction, while observing the length of limb lengthening, complications and function. RESULTS: Graft coverage of cases in the group were 16%-47% (mean, 26%), with 17 mm of the socket uncovered during operative evaluation. All patients were followed-up for 14-56 months (mean, 34.6 months). The lengthening of the affected limb was 2.9-4.6 cm (mean, (3.6 ± 0.7)cm). The limb-length discrepancy was 0-1.2 cm (mean, (0.6 ± 0.3)cm) after THA. The offset of the affected limbs was 26.4-34.3 cm(mean, (30.5 ± 1.6)cm). The postoperation radiography showed good position of the prosthetic components and coverage of the socket after bone graft was full. All patients had no static contraction abnormality of muscle in the affected limb. Three patients with numbness in lateral leg after the procedure recovered completely in one months. No other complication was observed except heterotopic ossification in 1 case. At the last follow-up examination, Harris hip score was 86 ± 11. There was statistical significance compared with the preoperative score (t = 5.86, P < 0.01) , and no revision was needed in all patients. CONCLUSION: Autograft of femoral head for acetabular reconstruction in THA without shortening femoral osteotomy for developmental dysplasia of the hip (DDH) is an effective procedure to reconstruct acetabulum and improve the socket bone coverage.

A reduction technique of arthroplasty without subtrochanteric femoral shortening osteotomy for the treatment of developmental high dislocation of hip: a case series of 28 hips.

In total hip arthroplasty for the treatment of developmental dysplasia of the hip (DDH) with high hip dislocation, it can be technically challenging to locate the true acetabulum and restore limb length without subtrochantric femoral shortening osteotomy. We explored and described total hip arthroplasty without subtrochanteric femoral shortening osteotomy in 28 hips with Crowe type III and IV dislocation by intravenous injection of rocuronium at 0.9mg/kg 1minute before reduction and hip reduction combined with continuous strong traction of the affected limb with patients in a position with hip and knee flexion. All patients did not show dislocation, prosthesis loosening, and other severe complications. It is thus a safe and feasible reduction technique for arthroplasty of Crowe type III or IV dislocation of DDH.

[Arthroscopic Bankart lesion repair by double-row vertical mattress suture with anchors for anteroinferior glenohumeral instability].

OBJECTIVES: To introduce a new arthroscopic Bankart repair by vertical mattress suture with anchors, and to evaluate its clinical effectiveness. METHODS: A new arthroscopic Bankart repair by vertical mattress suture with anchors was performed, including to insert only 2 anchors at 3 o'clock and 5 o'clock position and make vertical mattress suture of labrum-ligament complex at 2, 4 and 6 o'clock of labrum, and to shift up the anterior-inferior capsule. Nine cases of anterior glenohumeral instability without severe glenoid bone defect were followed-up for an average period of 14 months (range from 6 to 26 months). The average surgery age was 28 years (range from 21 to 46 years). RESULTS: The average surgery time was 51 min (40 - 75 min). Clinical scores as evaluated by the modified Rowe score advanced from 40 +/- 16 points to 92 +/- 19 points (75 - 94). There was no any recurrence and complication. External rotation was reduced by 5 degrees at 0 degrees adduction and by 3 degrees at 90 degrees of abduction. CONCLUSIONS: The arthroscopic Bankart repair by vertical mattress suture with anchors for anteroinferior glenohumeral instability is favorable as an easy, short-time surgery with excellent clinical results in short-term follow-up.