Small deviations between planned and performed bone cuts using a CT-based robotic-arm-assisted total knee arthroplasty system.

PURPOSE: Computed tomography (CT)-based robotic system for total knee arthroplasty (TKA) has shown improved accuracy compared to conventional. This study was designed to (1) confirm the accuracy of the robotic system in achieving the plan and (2) establish the alignment and positioning deviation between final components and planning, by measuring the discrepancy between final implant alignment and the corresponding planned cut. METHODS: Ninety-six cementless robotic-arm assisted (RA) TKAs were assessed. Bone resections were performed using the haptically controlled robotic arm. Alignment in the coronal and sagittal plane and resection depth of the distal femoral and proximal tibial cuts were recorded with a navigation planar probe. After final components were impacted, the probe was positioned on each implant surface to determine its alignment and positioning. RESULTS: The mean tibial resections and implanted tibial component's positioning were 0.4 mm (standard deviation, SD: 0.6) and 0.9 mm (SD: 0.8), respectively, higher than planned (p < 0.01). The tibial sagittal cut had 19/96 cases (19.8%) of ±1° outliers from plan. In 40/96 cases (41.7%), the tibial component was more prominent than planned of more than 1 mm. The mean femoral resections and impacted femoral component's positioning was 0.1 mm (SD: 0.8) and 0.2 mm (SD: 0.7), respectively, higher than planned. In 23/96 cases (24.0%), the femoral sagittal cut and femoral component coronal alignment deviated more than ±1° from plan. CONCLUSIONS: The computed tomography-based robotic-assisted TKA system showed good accuracy regarding bone preparation and component's positioning relative to the planning. Cementless tibial component impaction resulted in the most deviation from plan, with a large proportion of cases resulting in being more prominent than planned. LEVEL OF EVIDENCE: Level III.

Image-based robotic-arm assisted unicompartmental knee arthroplasty provides high survival and good-to-excellent clinical outcomes at minimum 10 years follow-up.

PURPOSE: The purpose of the present study was to determine the incidence of revision and report on clinical outcomes at a minimum of 10 years follow-up in patients who had received a medial unicompartmental knee arthroplasty (UKA) with an three-dimensional image-based robotic system. METHODS: A total of 239 patients (247 knees), who underwent medial robotic-arm assisted (RA)-UKA at a single center between April 2011 and June 2013, were assessed. The mean age at surgery was 67.0 years (SD 8.4). Post-operatively, patients were administered the Forgotten Joint Score-12 (FJS-12) and asked about their satisfaction (from 1 to 5). Post-operative complications were recorded. Failure mechanisms, revisions and reoperations were collected. Kaplan-Meier survival curves were calculated, considering revision as the event of interest. RESULTS: A total of 188 patients (196 knees) were assessed at a mean follow-up of 11.1 years (SD 0.5, range 10.0-11.9), resulting in a 79.4% follow-up rate. Seven RA-UKA underwent revision, resulting in a survivorship rate of 96.4% (CI 94.6%-99.2%). Causes of revision included aseptic loosening (2 cases), infection (1 case), post-traumatic (1 case), and unexplained pain (3 cases). The mean FJS-12 and satisfaction were 82.2 (SD 23.9) and 4.4 (SD 0.9), respectively. Majority of cases (174/196, 88.8%) attained the Patient Acceptable Symptoms State (PASS, FJS-12 > 40.63). Male subjects had a higher probability of attaining a "forgotten joint" (p < 0.001) and high satisfaction (equal to 5, p < 0.05), when compared to females. CONCLUSIONS: Three-dimensional image-based RA-UKA demonstrated high implant survivorship and good-to-excellent clinical outcomes at minimum 10 years follow-up. Pain of unknown origin represented the most common reason for RA-UKA revision. LEVEL OF EVIDENCE: III.

Management and Outcomes of Tibial Eminence Fractures in the Pediatric Population: A Systematic Review.

BACKGROUND: Tibial eminence fractures (TEF) of Meyers-McKeever type II-III-IV usually require surgical management. No consensus in the literature has been achieved regarding the best treatment option. The aims of the present systematic review were (1) to analyze the current literature and describe the outcomes of surgical treatment for TEF; and (2) to compare the outcomes of different surgical options using arthroscopic reduction and internal fixation (ARIF) with sutures or screws and open reduction and internal fixation (ORIF). METHODS: A search was carried out with Pubmed, Medline, and Cochrane. Key terms were used "tibial" AND "eminence" or "spine" or "intercondylar" AND "paediatric" or "children" AND "fracture" or "avulsion" AND "treatment". Twelve articles met the inclusion criteria. Demographic data, clinical outcomes, and complication rates were evaluated for each study. Means/standard deviation and sum/percentage were used for continuous and categorical variables, respectively. Chi-square or t-student tests were applied. A p-value < 0.05 was considered statistically significant. RESULTS: ORIF showed superior clinical outcomes (Tegner (p < 0.05) and Lysholm (p < 0.001) scores) relative to ARIF and a lower incidence of arthrofibrosis (p < 0.05) and implant removal (p < 0.01). The Tegner, IKDC, and Lysholm scores showed statistically significant superior results following arthroscopic sutures compared to arthroscopic screws (p < 0.001). The incidence of arthrofibrosis was higher after arthroscopic sutures (p < 0.05), the implant removal was higher after screw fixation (p < 0.001) Conclusions: Better clinical results with low complication rates were achieved with ORIF surgery rather than ARIF; arthroscopic suture fixation resulted in higher clinical results compared to arthroscopic screw fixation and reduced the incidence of postoperative complications.

Total knee arthroplasty in-vivo kinematics changes after insert replacement for posterior cruciate ligament deficiency: a case report.

In cruciate-retaining (CR) total knee arthroplasty (TKA) the preservation of the posterior cruciate ligament (PCL) provides joint stability and drives knee kinematics. No previous studies described in-vivo knee kinematics of PCL-deficient CR TKA. In the present case report it's described the in-vivo kinematic pattern change in a patient with post-operative PCL failure before and after insert replacement to a cruciate substituting (CS) design. In-vivo fluoroscopic analysis showed that PCL-deficient TKA showed more anterior translation of the lateral femoral condyle with respect to a cohort  of patients operated of CR-TKA with intact PCL, undergoing fluoroscopic analysis. The replacement to a CS design provided more external rotation of the femoral component and less anterior motion of the lateral condyle. The antero-posterior translation of the medial condyle was similar in PCL-deficient knee, CS TKA and controls. TKA with PCL deficiency showed more antero-posterior motion compared to TKAs with intact PCL and this can be source the of instability and a potential factor for patient's dissatisfaction. For this reason surgeons should attentively verify PCL integrity when performing a cruciate-sparing TKA.

[The sentinel lymph node biopsy. Evolution and convalidation of the technique]. / La biopsia del linfonodo sentinella. Evoluzione e convalidazione della tecnica.

BACKGROUND: Sentinel node biopsy is a minimally invasive technique alternative to routine axillary dissection in breast cancer staging. This technique selects women with positive nodes who may benefit from axillary dissection, avoiding unnecessary operations in negative node biopsies. AIMS: In this article we report a 5 year multi disciplinary experience in sentinel node biopsy involving the General Surgery Unit of Imola Hospital in collaboration with Radiologist, Pathologists and Specialists in Nuclear Medicine. METHODS: From 2000 to 2004 the Authors treated 209 women performing 214 sentinel node biopsies (in 5 cases the tumor was bilateral). Sentinel node identification was undertaken by lymphoscintigraphy; in 15 cases we associated intradermal injection of blue dye. Lymph nodes were examined by at least 60 hematoxylin and eosin stained sections and when nodes found negative were further studied with immunohistochemical stains for cytokeratins. RESULTS: Sentinel node identification rate was 99.1%. In 62 patients sentinel node was metastatic and in 17 such nodes micrometastases were detected. In 6 cases with single metastatic cells, axillary dissection was not perfomed, in accordance to current opinions. In 50 of 62 women with metastatic axillary nodes (80.6%) the sentinel node was the only metastatic one. Number of axillary dissections decreased of more than 70% in four years, from theoretical 214 to 62. CONCLUSION: Sentinel node biopsy is currently a validated technique and many breast cancer patients are spared a regional lymph node dissection without compromising local control and the accuracy of staging.