Flexion contracture can cause component mismatch in the Prophecy® preoperative patient-specific instrumentation for Evolution® medial-pivot knee system.

INTRODUCTION: Patient-specific instrumentation (PSI) systems are used to conduct total knee arthroplasty. PSI reduces operative time, is less invasive and easier to use, and minimizes the risk of errors by providing precise measurements and reducing operating room turnover time. However, a study on the accuracy of Prophecy Evolution PSI (Microport Inc., Arlington, TN, USA) reported that 94% were below the error margin of 1.5 mm and 90% had error margins of 1 mm. This study aimed to evaluate the accuracy of the Prophecy Evolution PSI system in terms of the thickness of "total" bony resection required to achieve adequate extension/flexion gaps and the component match ratio between preoperative planning and actual component size inserted. METHODS: Comparisons were made between the sizes of femoral and tibial components planned with PSI and those inserted. The primary outcome was the average preoperative range of motion with and without matched femoral/tibial components. The study further analyzed the proportions of cases in which both the femoral and tibial components matched, neither matched, and only one of the femoral or tibial components matched. RESULTS: The ratio of the same sizes between the PSI planning and those inserted was 50.8% (33 patients) for both the femoral and tibial components. For the femoral component alone, the ratio was 84.6% (55 patients), and for the tibial component, it was 58.4% (38 patients). A receiver-operating characteristic curve analysis indicated that flexion contracture greater than 20° was a significant prognostic factor for the PSI component match group versus the mismatch group. DISCUSSION: Flexion contracture may cause PSI mismatch. Notably, flexion contracture greater than 20° was a significant risk factor for the PSI component match group versus the mismatch group. During preoperative planning for a patient with flexion contracture, surgeons should prepare for the possibility of inserting an undersized tibial component.

Relationship Between Intraoperative Macroscopic Anterior Cruciate Ligament Findings, Perioperative Surgical Findings, and Postoperative Clinical Outcome After Cruciate-Retaining Total Knee Arthroplasty.

PURPOSE: To assess how intraoperative macroscopical anterior cruciate ligament (ACL) findings affect perioperative procedures, biomarkers, and postoperative anterior-posterior (AP) laxity and range of motion (ROM) after cruciate-retaining (CR) total knee arthroplasty (TKA) and to determine how chronic ACL deficiency may affect postoperative inflammatory biomarker, AP laxity, and ROM. METHODS: A total of 121 patients with varus knee osteoarthritis without a history of ACL injury who underwent ATTUNE® (DePuy Synthes, Warsaw, IN) CR TKA were analyzed. Intraoperative ACL findings were stratified into intact, damaged, and diminished, according to the tension by probing, synovial coverage, and vascularity. C-reactive protein (CRP) levels were examined at one, seven, and 14 days after surgery. Knee AP laxity measurements using Kneelax 3 (Monitored Rehab Systems, Haarlem, The Netherlands) and postoperative knee ROM were also compared. RESULTS: One-way ANOVA showed significant differences in CRP levels examined one day after surgery observed between the three groups (8.4 (3.8), 9.8 (4.3), and 13.2 (7.7) mg/dL, respectively; P = 0.018), with post hoc analysis showing that CRP levels one day after surgery were significantly greater in the diminished group than in the intact and damaged groups (P = 0.012 and 0.023, respectively). AP laxity in 30° of knee flexion was observed between the three groups (5.4 (2.3), 5.8 (2.5), and 7.1 (2.8) mm, respectively; P = 0.039), with post hoc analysis showing that AP laxity in 30° of knee flexion was significantly greater in the diminished group than in the intact group (P = 0.038). Knee ROM showed no significant differences. CONCLUSION: Intraoperative ACL diminishment was associated with higher CRP one day after surgery and midrange AP laxity one year after surgery.

Plate Hooking Transtibial Medial Meniscus Posterior Root Pull-Out Repair with Medial Open-Wedge High Tibial Osteotomy for Knee Osteoarthritis with Medial Meniscus Posterior Root Tear.

Medial meniscus posterior root tears (MMPRT) are a risk factor for knee osteoarthritis (KOA) because it involves disruption of the hoop structure of the meniscus. In recent years, MMPRT pullout repair has been performed to restore the native anatomy of the meniscus attachment. In addition, medial open-wedge high tibial osteotomy (MOWHTO) has been performed with MMPRT pullout repair to reduce the pressure on the medial compartment. However, it has been noted that when MMPRT pullout repair and HTO are performed simultaneously in a patient, the locking screws of the plate interfere with the tibial bone tunnel, which damages the suture. In this technical note, we developed a method to reduce the probability of interference by placing the plate further anteroinferior when digging the bone tunnel from the PM position. This technical note aimed to provide a comprehensive description of the safety of transtibial MMPRT repair with MOWHTO for medial KOA with MMPRT.

Association between intraoperative findings and postoperative knee range motion after cruciate-retaining total knee arthroplasty.

BACKGROUND: Total knee arthroplasty (TKA) alleviates pain and improves daily living activities in individuals with end-stage osteoarthritis of the knee. However, up to 20% of patients have sub-optimal outcomes after TKA. OBJECTIVE: No studies have clarified the intraoperative factors that affect postoperative range of motion (ROM) after cruciate-retaining (CR) TKA. Thus, this study aims to clarify these factors. METHODS: Patients with knee osteoarthritis with varus knee deformity who underwent CR-TKA between May 2019 and December 2020 were included in this study. One year after surgery, patients were stratified into two groups based on knee flexion: Group F (over 120∘) and Group NF (below 120∘). Patient backgrounds including age, body mass index, hip knee angle, preoperative range of motion for both extension and flexion, intraoperative center joint-gap measurements of 0∘, 30∘, 45∘, 60∘, 90∘, and 120∘ of knee flexion using a tensor, intraoperative anterior-posterior (AP) laxity measurements of 30∘ and 90∘ of knee flexion using an instrumental laximeter were compared between the groups. Univariate analyses between the groups were used to construct the initial model. The receiver operating characteristic curve was also analyzed. The predictive variables included in the final model were selected by stepwise backward elimination. RESULTS: Intraoperative AP laxity with 30∘ of knee flexion smaller than 10.8 mm was a significant positive prognostic factor (OR: 1.39, 95% CI: 1.08-1.79, P= 0.011) of postoperative ROM over 120∘ of knee flexion one year after surgery. The sensitivity, specificity, PPV, and NPV were 70.9%, 82.4%, 92.9%, and 46.7%, respectively. CONCLUSION: Intraoperative AP laxity smaller than 10.8 mm was a significant positive predictive factor for obtaining knee flexion greater than 120∘ one year after surgery when using CR-TKA and its PPV was high up to 92.9%.

Use of a preoperative 3D templating and proximal lateral tibial fitting patient-specific instrumentation in fixed valgus complex primary total knee arthroplasty for a patient with retaining hardware for internal fixation to treat Schatzker type V tibial plateau fracture: A case report.

A 72-year-old female patient with a fixed valgus knee deformity due to a Schatzker type V tibial plateau fracture treated with bilateral locking plates 8 years ago was admitted to our clinic with complaints of chronic pain and knee instability when walking. Radiographs revealed Kellgren-Lawrence Classification grade 4 knee osteoarthritis and 20.5° of valgus knee deformity. She was treated with three-dimensional templating and proximal lateral tibial fitting patient-specific instrumentation-assisted mechanically aligned posterior sacrificing total knee arthroplasty with minimal removal of the retained hardware for the internal fixation of the tibial plateau fracture via a lateral approach, resulting in a favorable clinical outcome. The use of proximal lateral tibial fitting patient-specific instrumentation in fixed valgus complex primary total knee arthroplasty for patients with retaining hardware for internal fixation to treat tibial plateau fractures is considered a treatment option to decrease surgical invasion.

Habitual patellar dislocation 40 years after failed conservative treatment: A case report.

Patellar dislocation is often caused by congenital bone morphological abnormalities or joint laxity and is rarely traumatic. We report a case of long-term habitual patellar dislocation due to trauma 40 years ago without abnormal bone morphology, which required a combined procedure, including the Elmslie-Trillat (ET) procedure, massive lateral release, and medial patellofemoral ligament (MPFL) reconstruction, resulting in favorable outcomes. A 52-year-old male, with no specific underlying disease, dislocated his right patella due to falls when he was 13 years old and underwent conservative treatment. Subsequently, patellofemoral instability remained, and the patella began dislocating outward every time he flexed his knee joint; however, he could walk without pain. Therefore, he left it untreated for more than 40 years. His Lysholm and Kujala scores were 77 and 73 points, respectively. Radiographs showed no abnormal bone morphology with a tibial tuberosity-tibial groove (TT-TG) distance of 12 mm and a tibial external rotation angle of 5°. We released the distal iliotibial ligament and lateral bursa following the Fulkerson procedure, and the patella was stabilized from 0° to 60° of knee flexion. The ET procedure was subsequently performed. The patella was moved 13 mm medially and fixed using tibial coarse translation, which stabilized the patella up to 90°. However, when flexed beyond 90°, the patella was displaced laterally; therefore, MPFL reconstruction with autologous hamstring tendon was performed. Range of motion exercises were initiated 1 day postoperatively. Partial and full weight-bearing were allowed 2 and 4 weeks postoperatively, respectively. At the final outpatient follow-up at 8 months postoperatively, the patient could walk without patellofemoral instability; the Lysholm and Kujala scores had recovered from 77 to 97 and from 73 to 93 points, respectively. This combined patellofemoral-stabilizing procedure is considered the treatment of choice for patients with habitual patellar dislocation despite the chronicity.

Restoration of the Knee Medial Collateral Ligament and Complete Soft-tissue Coverage After Medial Open-Wedge High Tibial Osteotomy.

High tibial osteotomy (HTO) is used in the treatment of knee osteoarthritis. This surgical procedure is indicated in patients with medial osteoarthritis who are relatively young and active and have a good range of motion. In most medial open-wedge HTO cases, the fascia, medial collateral ligament (MCL), and part of the knee joint capsule are carefully separated and moved to expose the osteotomy site, but many patients experience postoperative swelling and pain in the affected limb due to bleeding from the osteotomy site and MCL failure. We have developed a method of osteotomy followed by a restoration of the MCL to its anatomic position and complete soft-tissue coverage of the osteotomy. This Technical Note aims to provide a comprehensive description of the employment of a soft-tissue envelope for the MOW-HTO protection.

Intraoperative Laximetry-Based Selective Transtibial Anterior Cruciate Ligament Reconstruction Concomitant With Medial Open Wedge High Tibial Osteotomy for Treating Varus Knee Osteoarthritis With Anterior Cruciate Ligament Deficiency.

High tibial osteotomy (HTO) is used in the treatment of varus knee osteoarthritis (KOA) in young and active patients. At times, a concomitant anterior cruciate ligament (ACL) deficiency is found, and there is no conclusive evidence comparing the osteotomy options for an ACL-deficient knee despite the popularity of medial opening-wedge (MOW) HTO in varus KOA with ACL deficiency. To minimize the incidence of an unnecessary ACL reconstruction with MOW-HTO, we developed an intraoperative laximetry-based selective technique for transtibial ACL reconstruction concomitant with MOW-HTO using a sterilizable metal laximeter. To successfully use the device required for this procedure, surgeons must understand the proper techniques. Hence, this Technical Note aims to give a comprehensive description of the technique.

Can tibia-first total knee arthroplasty using computer-assisted system improve anterior and posterior knee stability?

BACKGROUND: Total knee arthroplasty (TKA) is a widely performed procedure to alleviate pain and restore function of patients with end-stage knee osteoarthritis. OBJECTIVE: The study aim was to determine if tibia-first (TF) total knee arthroplasty (TKA) using a novel computer-assisted surgery (CAS) system can yield better anterior and posterior (AP) knee stability. METHODS: Patients with knee osteoarthritis with obvious varus knee who met the indication for and underwent TKA from May 2019 to November 2020 were included. Forty-one measured resection (MR)-TKAs and 32 TF-TKAs were compared. The varus-valgus ligament balance and joint tension at a joint center-gap setting equal to the tibial-baseplate thickness were measured, and appropriate polyethylene inserts with 0∘, 30∘, 45∘, 60∘, 90∘, and 120∘ of knee flexion were placed. A Kneelax 3 arthrometer was used to measure knee AP laxity in the postoperative anesthetized patients with 30∘ and 90∘ of knee flexion. RESULTS: The horizontal gap balance was significantly closer in the TF-TKA group than the MR-TKA group for 0∘, 30∘, 45∘, and 60∘ of knee flexion. In contrast, no significant differences were observed for 90∘ and 120∘ of knee flexion. No significant differences in joint-gap tensions among all knee-flexion angles were observed. Translation was significantly smaller in the TF-TKA group than the MR-TKA group for AP laxity with 30∘ of knee flexion (8.8 ± 2.9 mm vs. 10.7 ± 3.1 mm, P= 0.0079). In contrast, no significant AP laxity was observed with 90∘ of knee flexion (7.2 ± 2.8 mm vs. 7.2 ± 3.5 mm). CONCLUSION: TF-TKA using a novel CAS system provided better AP knee stability with close to horizontal gap balances.

Compartment syndrome after transtibial anterior cruciate ligament reconstruction: A case report.

Compartment syndrome is a rare complication after anterior cruciate ligament (ACL) reconstruction. This is one of the most devastating complications after surgery of the lower limb, with certain risks of renal failure, shock, and even death. We report a case of compartment syndrome that occurred 12 h after ACL reconstruction. A healthy 67-year-old male who underwent transtibial ACL reconstruction using autogenous hamstring tendon graft complained of progressive intense pain, paresthesia, and paresis. He had a pallid aspect and taut, shiny skin with several blisters around the medial aspect of the lower limb. Computed tomography revealed a hematoma that originated from the tibial bone tunnel. The patient was immediately referred for an urgent decompression fasciotomy. Hematoma debridement, medial fasciotomy, and negative-pressure wound therapy were performed. The patient recovered well and received routine postoperative physiotherapy.

Blast injury of the finger caused by mobile battery explosion: A case report.

Lithium-ion batteries can cause several types of injuries upon explosion due to misfire. We report a case in which a mobile battery explosion resulted in high-pressure injection of metal debris into a small entry point on the skin creating puncture wounds on a patient's index finger, necessitating surgical intervention for massive debridement. A healthy 45-year-old, right-hand-dominant woman presented to the emergency department 4 h after a mobile battery had exploded in her left hand, causing burns to the left index finger. The battery had exploded due to misfire because the patient had accidentally hit it with a hammer. Radiographs of the index finger demonstrated foreign material extending from the fingertip to the ulnar proximal phalanx along the flexor tendon sheath, which was consistent with a high-pressure injection injury. She underwent semiurgent incision, irrigation, and debridement of the left index finger the day after the injury. The wound healed uneventfully within a month. At the 6-month follow-up, the palm-to-tip distance was 1 cm, and sensation at the tip was recovered. Compositional analysis of the debris revealed that the two major elements were aluminum and nickel (both less than 10%); lithium constituted less than 1% of the debris, a level deemed safe in humans. The protocol of semiurgent incision, irrigation, and debridement was safe and effective in the treatment of the injection injury caused by the mobile battery explosion.