Different femoral rotation with navigated flexion-gap balanced or measured resection in total knee arthroplasty does not lead to different clinical outcomes.

PURPOSE: Femoral rotation in total knee arthroplasty (TKA) is hypothesized to vary in the same knee depending on the method used to establish it. METHODS: Thirty-eight patients who underwent TKA surgery using a measured resection technique (RT) were compared with 40 patients who underwent a flexion-gap balancing technique with computer-assisted (for navigation) surgery (FB-CAS) to assess clinical and radiographic alignment differences at two years postoperatively. In 36 of the 40 patients in the FB-CAS group, both methods were used. Intraoperatively, the transepicondylar femoral rotation (TEFR) in reference to the transepicondylar axis was established as the rotation that balanced the flexion gap. Once the TEFR was obtained, an analogous rotation as measured by a posterior reference femoral rotation (PRFR) cutting guide was determined. RESULTS: Femoral component rotation determined by the TEFR and PRFR methods differed in each of the knees. The median TEFR was 0.08°±0.6° (range - 1.5°, 1.5°), and the median PRFR was 0.06°±2.8° (range - 6°, 5°). The mean difference in the rotational alignment between the TEFR and PRFR techniques was 0.01° ± 3.1°. The 95% limits of agreement between the mean differences in measurements were between 6.2° external rotation and - 6.1° internal rotation. At 2 years postoperatively, we found no differences in the radiographic or clinical American Knee Society score between the two groups. CONCLUSION: Rotation of the femoral component in TKA can vary in the same knee depending on the surgical method used to establish it. This variation in femoral rotation is sufficiently small enough to have no apparent effect on the 2-year clinical outcome score. LEVEL OF EVIDENCE: II.

Clinical results and complications of a two-stage procedure in hip infection using preformed antibiotic-loaded cement spacers.

Antibiotic-loaded cement spacers are used in two- stage hip replacement. The aim of our study was to compare our results using a Spacer-G with previous results reported in the literature. From June 2002 to April 2010, all patients treated with a two-stage revision were retrospectively reviewed. On the basis of the results of the first-stage procedure, 52 patients underwent the second stage, six developed a dislocation, in eight the spacer was maintained, and five patients developed an acute infection of the spacer or the infection was not resolved. With regard to the second-stage procedure the revision was successful in 44 patients, a re-infection developed in four patients and the definitive prosthesis presented a mechanical complication in four more. The literature results reported that 97.5% of the spacers were reimplanted, although 12.09% of them developed a dislocation. Surgeons must assess several aspects so as to avoid mechanical complications like dislocation and re- infections during the two stages of the procedure.

Dislocation of preformed antibiotic-loaded cement spacers (Spacer-G): etiological factors and clinical prognosis.

This study assesses the factors associated with the dislocation of the Spacer-G and its clinical prognosis. Seventy-four spacers were reviewed. Acetabular bone defects, proximal femoral cementation of the spacer and its relationship to the size of the head spacer were not associated with dislocation. The only variable that it was possible to associate with dislocation was when the previous stem, prior to the spacer placement, was a cemented stem. In patients who experienced a dislocation, infection was not cured during the interim period more frequently than patients who had not experienced a dislocation (P = 0.001) and the final clinical hip evaluation was also worse (P < 0.001). The study concludes that the surgeon should assess different surgical aspects in order to avoid mechanical complications such as dislocation and its consequences.

Radiological evaluation of acetabular erosion after antibiotic-impregnated polymethylmethacrylate spacer (Spacer-G).

Different types of hip spacers have been described (hand-made, custom-molded or prefabricated) for treatment of a chronic hip infection. A potential disadvantage of monoblock prefabricated spacer is that it may cause acetabular bone loss. This study assesses the radiological acetabular erosion using an antibiotic-impregnated pre-fabricated polymethylmethacrylate Spacer-G. We retrospectively reviewed the radiographs of thirty five patients who were managed with Spacer-G to treat chronic hip infection. No acetabular erosion were observed in thirty two patients with a mean time from the first to second stage and from the first to the last radiograph of 5.09 and 3.77 months respectively. In three patients the time between the radiographs was more than one year and the second stage was not performed; two developed a protrusion acetabuli whereas the other one a destruction of the acetabular roof. Using a Spacer-G in chronic hip infection treatment for less than one year is not associated with radiological acetabular erosion if the patient is maintained at partial weight bearing.

A feasibility study of home-based preoperative multimodal physiotherapy for patients scheduled for a total knee arthroplasty who catastrophize about their pain.

BACKGROUND: Preoperative pain catastrophizing (PC) and pain are both risk factors for poor outcomes after a total knee arthroplasty (TKA). Despite that, there is limited evidence about physiotherapy interventions' effectiveness on addressing such factors. PURPOSE: To evaluate the feasibility and clinical impact of a home-based multimodal physiotherapy intervention in reducing pain and PC, in patients scheduled for a TKA who present preoperative moderate-to-severe pain and PC. METHODS: Three-armed parallel-group randomized controlled feasibility study. Subjects with symptomatic osteoarthritis and a score of ≥ 20 on the Pain Catastrophizing Scale (PCS) were recruited. The control group received usual care. Both experimental groups received pain neuroscience education, coping skills training and therapeutic exercise, but differ in the number of sessions, dosage, hands-on approach, and grade of supervision. All outcomes were measured before and after the intervention. RESULTS: A total of 33,7% were eligible for inclusion, and 97,1% agreed to participate. Every participant completed the treatment. Treatment compliance was higher in the group with additional supervision. Both groups showed significant effects in PC and pain reduction. A total of 33 patients would be required for a full trial. CONCLUSION: Preoperative physiotherapy is a feasible and effective treatment in reducing pain intensity and PC in high PCS osteoarthritis subjects scheduled for a TKA.

Location, Clinical Presentation, Diagnostic Algorithm and Open vs. Arthroscopic Surgery of Knee Synovial Haemangioma: A Report of Four Cases and a Literature Review.

Objective: The aim was to report 4 patients with intra-articular knee synovial haemangioma (KSH) and to perform a systematic review to describe the patient characteristics, patterns of tumor location, clinical presentation, usefulness of imaging examinations, pros and cons of arthroscopic vs. open resection, and follow-up in the literature. Design: From 1996 to 2016, four patients with KSH were retrospectively reviewed. A literature search was conducted in PubMed from 2000/01 to 2020/06 using the search terms "synovial haemangioma" and "knee." Fifty full-text articles that included a total of 92 patients were included for further discussion. Results: Four adults (20-40 years) were diagnosed with KSH. Three lesions located in the suprapatellar pouch, two eroding the patella and one the supratrochlear bone, and one in the posterior compartment. Persistent anterior knee pain was the main complain. MRI revealed a benign tumor mass in all cases except one. Open excisional biopsy and regional synovectomy were performed in three patients, and by arthroscopy of the posterior compartment in the fourth. Histological type was arteriovenous in three cases and capillary in one. A pain-free knee without recurrence was achieve in all cases except one, which was successfully reoperated. Average follow-up time was 3.5 years. A literature review showed that KSH appears most frequently in children and teenagers (64.6%) and does not differ by gender. The suprapatellar and patella-femoral joint compartment was the most frequent location (47.9%). The bony tissue of the knee was rarely affected (13.5%). Pain, swelling and haemarthrosis were frequently reported (88.2, 66.7, and 47.1%). MRI was the most commonly used imaging test (98%). Treatment consisted of regional synovectomy by open surgery or arthroscopy in 66.7 and 15.6% of cases, respectively. Conclusions: KSH should be considered in the differential diagnosis of adult patients with chronic low-intensity knee pain. MRI is the most useful exam because it establishes the location, extent and benign characteristics of the tumor. Definitive diagnosis requires histological examination. We believe excisional biopsy and regional synovectomy by arthroscopy should be the treatments of choice for intra-articular tumors, but we recommend open surgery when the lesion extends to the tendons, muscle or bone.

Relationship between femoral offset and dislocation in preformed antibiotic-loaded cement spacers (Spacer-G®).

INTRODUCTION: A reduction in femoral offset may decrease muscle tension and lead to spacer dislocations even though proximal femur, musculature and acetabulum remain intact. In this study, we aimed to determine whether postoperative lateral femoral offset (LFO) and modified vertical femoral offset (MVFO) values affect the risk of dislocation of a hip spacer. MATERIALS AND METHODS: We measured LFO and MVFO in properly centred, postoperative, anteroposterior radiographs of the pelvis in 66 patients (71 spacers). We then compared the operated and non-operated sides and recorded any dislocations. RESULTS: Although LFO decreased (p<0.001), the reduction was not associated with dislocation (p = 0.471). MVFO remained unchanged after spacer implantation (p = 0.277) and was not associated with dislocation (p = 0.418). CONCLUSIONS: In conclusion, the preformed spacer decreased LFO but not MVFO compared with the contralateral hip. The variations did not significantly affect the dislocation rate.

Prosthetic joint infections due to Staphylococcus aureus and coagulase-negative staphylococci.

PURPOSES: To evaluate the specific characteristics, outcome, and predictors of failure of prosthetic joint infections (PJI) due to S. aureus and coagulase-negative staphylococci (CNS) treated with open debridement and retention of the implant. METHODS: PJI due to S. aureus or CNS prospectively registered in a database from 1999 to 2009 were retrospectively reviewed. During the study period, 106 patients met the inclusion criteria. The mean follow-up period was 3.8 years and for at least 2 years in all patients. The failure rate was 23.6% (25 out of 106). The only variable significantly associated with failure in the global cohort was polymicrobial infection (38.7% vs. 17.3%, p = 0.024). Fifty-seven (53.8%) patients had an infection due to S. aureus and 49 (46.2%) due to CNS. Among S. aureus infections, 95% corresponded to primary arthroplasties while 98% of PJIs due to CNS were after revision arthroplasties (p<0.001). C-reactive protein was significantly higher in PJI due to S. aureus (9.5 mg/dl vs. 4.9 mg/dl, p = 0.007). The rate of methicillin-resistance (8.8% vs. 59.2%, p<0.001) and fluoroquinolone-resistance (15.8% vs. 34.7%, p = 0.005) was significantly higher in CNS infections. The global failure rate was higher in S. aureus infections (28% vs. 18.3. p = 0.26). In S. aureus infections, patients diagnosed within the first 15 days after joint arthroplasty (p = 0.031) and with bacteremia (p = 0.046) had poor pro-gnosis. In CNS infections only the location of the prosthesis (knee 27.6% vs. hip 5%, p = 0.045) was associated with failure. CONCLUSIONS: PJIs due to S. aureus were mainly in primary arthroplasties; they had a higher inflammatory response; and the strains were more susceptible to fluoroquinolones and methicillin than CNS infections. S. aureus infections had a higher failure rate than CNS infections, however, the difference was not statistically significant. There were few factors associated with failure and they were different in S. aureus and CNS infections.