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.

Similar survivorship at the 5-year follow-up comparing robotic-assisted and conventional lateral unicompartmental knee arthroplasty.

PURPOSE: This retrospective study aims to analyse the survivorship and functional outcomes of two samples with similar preoperative clinical and demographic data of lateral unicompartmental knee arthroplasty (UKA) performed with robotic and conventional surgery at a minimum 5-year follow-up. METHODS: In this retrospective study, the clinical records of two cohorts for 95 lateral UKA implants were analysed. The first cohort consisted of 43 patients with cemented lateral UKA performed with the conventional procedure (Conventional group). The second cohort consisted of 52 patients who received robot-assisted cemented lateral UKA (Robotic group). Clinical evaluation of the two samples entailed evaluating the Knee Injury and Osteoarthritis Outcome Score divided into subscales (symptoms and stiffness, pain, function in daily living, function in sport and recreation and quality of life) for each patient. Revision was defined as the failure of the implant (periprosthetic joint infection, periprosthetic fracture or aseptic loosening), and survival was based on implant revision. RESULTS: The mean follow-up time was 90.3 ± 9.1 months for the Conventional Group and 95.4 ± 11.0 months for the Robotic Group (n.s.). Each patient was clinically evaluated on the day before surgery (T0), at a minimum 1-year follow-up (T1) and at a minimum 5-year follow-up (T2). In both groups, all clinical scores improved between T0 and T1 and between T0 and T2 (p < 0.05); for both groups, no differences were noted in any clinical scores between T1 and T2 (n.s.). No significant differences in any clinical score were found between the two groups at each follow-up (n.s.). Survival analysis reported no differences between the two groups at the final 1-year follow-up, with three failures (2 aseptic loosening and 1 periprosthetic fracture) in the Conventional group and two failures (1 patellofemoral osteoarthritis and 1 inexplicable pain) in the Robotic group (n.s.). CONCLUSIONS: This study shows excellent clinical outcomes and revision rates in robotic arm-assisted and manual techniques for lateral UKA, with no clinical differences at medium- to long-term follow-up. LEVEL OF EVIDENCE: Level III-comparative study.

Robotic Arm-Assisted Lateral Unicompartmental Knee Arthroplasty: How Are Components Aligned?

The purpose of this multicenter, retrospective, observational study was to investigate the association between intraoperative component positioning and soft tissue balancing, as reported by robotic technology for a cohort of patients who received robotic arm-assisted lateral unicompartmental knee arthroplasty (UKA) as well as short-term clinical follow-up of these patients. Between 2013 and 2016, 78 patients (79 knees) underwent robotic arm-assisted lateral UKAs at two centers. Pre- and postoperatively, patients were administered the Knee Injury and Osteoarthritis Score (KOOS) and the Forgotten Joint Score-12 (FJS-12). Clinical results were dichotomized based upon KOOS and FJS-12 scores into either excellent or fair outcome, considering excellent KOOS and FJS-12 to be greater than or equal to 90. Intraoperative, postimplantation robotic data relative to computed tomography-based components placement were collected and classified. Following exclusions and loss to follow-up, a total of 74 subjects (75 knees) who received robotic arm-assisted lateral UKAs were taken into account with an average follow-up of 36.3 months (range: 25.0-54.2 months) postoperative. Of these, 66 patients (67 knees) were included in the clinical outcome analysis. All postoperative clinical scores showed significant improvement compared with the preoperative evaluation. No association was reported between three-dimensional component positioning and soft tissue balancing throughout knee range of motion with overall KOOS, KOOS subscales, and FJS-12 scores. Lateral UKA three-dimensional placement does not seem to affect short-term clinical performance. However, precise boundaries for lateral UKA positioning and balancing should be taken into account. Robotic assistance allows surgeons to acquire real-time information regarding implant alignment and soft tissue balancing.

Preoperative Osteoarthritic Grade Affects Forgotten Joint Status and Patient Acceptable Symptom State After Robotic Arm-Assisted Unicompartmental Knee Arthroplasty.

BACKGROUND: This retrospective observational study was designed to investigate the association between radiographic Ahlbäck osteoarthritis (OA) grade and postoperative joint perception in a cohort of patients undergoing medial robotic arm-assisted unicompartmental knee arthroplasty (RA-UKA), using the Forgotten Joint Status and Patient Acceptable Symptom State (PASS) as outcomes. METHODS: Between January 2014 and May 2019, 660 patients (719 knees) underwent medial RA-UKA at 2 centers. Ahlbäck OA grade was measured on preoperative knee radiographs. Postoperatively, patients were administered the Forgotten Joint Score-12 (FJS-12) and 5-level Likert scale to assess patients' satisfaction. Correlations were described among FJS-12, satisfaction, and Ahlbäck OA grade by means of logistic regression models. RESULTS: A total of 547 patients (602 knees) were assessed at a mean follow-up of 3.5 years (standard deviation 1.4). A total of 293 cases were graded as Ahlbäck 1 (Group A) and 309 knees were graded as Ahlbäck>1 (Group B). Statistically significant difference was detected in mean FJS-12 (P < .001), but not in the postoperative satisfaction level (P = .06) between the 2 groups. Patients in Group B had a significantly higher probability of attaining a "forgotten knee" after the operation, compared to Group A (P < .05). Cases in Group A had a significantly lower probability of achieving the PASS (P < .01). CONCLUSION: Patients with higher grades of OA (Ahlbäck>1) were more likely to attain a "forgotten knee," while patients with less severe OA (Ahlbäck 1) were less likely to achieve the PASS after RA-UKA. Although patients with less severe OA reported fairly good outcome, cases in which the results will be poorer are currently difficult to predict.

Robotic arm-assisted unicompartmental knee arthroplasty: high survivorship and good patient-related outcomes at a minimum five years of follow-up.

PURPOSE: Robotic arm-assisted unicompartmental knee arthroplasty (RA-UKA) has been shown to improve component placement, reduce intraoperative variability, increase patient satisfaction and improve short-term survivorship results. The aim of this retrospective study was to determine the incidence of revision and the clinical performance at a minimum of 5-year follow-up for a cohort of patients who received a medial RA-UKA. METHODS: Between April 2011 and July 2013, a total of 254 patients underwent medial RA-UKA at a single centre. Clinical performance was investigated using the Forgotten Joint Score-12 (FJS-12) and a 5-level Likert scale made of five items to assess joint perception and patient satisfaction. Kaplan-Meier implant survivorship was calculated and reasons for revision were collected. The effect of age, gender and body mass index (BMI) on the probability of reporting high FJS-12 and satisfaction were assessed. RESULTS: After considering exclusion criteria and loss to follow-up, a total of 216 patients (224 medial RA-UKAs) were assessed at a mean 5.9 years of follow-up. Five RA-UKAs underwent implant revision, resulting in an overall Kaplan-Meier survivorship of 97.8%. Unexplained knee pain (0.9%) was the most common reason for RA-UKA revision. Good-to-excellent FJS-12 scores and high satisfaction levels were reported at mid-term follow-up. Male patients had higher probability of having FJS-12 > 90 (p < 0.05) and high satisfaction levels (p < 0.05). CONCLUSIONS: RA-UKAs demonstrated high survivorship and good-to-excellent patient-reported outcome measures and satisfaction levels at minimum 5-year follow-up. Results for male patients had improved clinical performance when compared to female subjects. LEVEL OF EVIDENCE: IV.

Clinical results and short-term survivorship of robotic-arm-assisted medial and lateral unicompartmental knee arthroplasty.

PURPOSE: The aim of this multicentre, retrospective, observational study was to determine the incidence of revision and clinical results of a large cohort of robotic-arm-assisted medial and lateral UKAs at short-term follow-up. It was hypothesized that patients who receive robotic-arm-assisted UKA will have high survivorship rates and satisfactory clinical results. METHODS: Between 2013 and 2016, 437 patients (470 knees) underwent robotic-arm-assisted medial and lateral UKAs at two centres. Knee Injury and Osteoarthritis Outcome Score (KOOS), Forgotten Joint Score 12 (FJS-12) and Short-Form Physical and Mental Health Summary Scales (SF-12) were administered to estimate patients' overall health status pre- and post-operatively. Results were dichotomized as 'excellent' and 'poor' if KOOS/FJS-12 were more than or equal to 90 and SF-12 was more or equal to 45. Associations between patients' demographic characteristics and clinical outcomes were investigated. Post-operative complications and pain persistence were recorded. RESULTS: Following exclusions and losses to follow-up, 338 medial and 67 lateral robotic-arm-assisted UKAs were assessed at a mean follow-up of 33.5 and 36.3 months, respectively. Three medial UKAs were revised, resulting in a survivorship of 99.0%. No lateral implants underwent revision (survivorship 100%). On average, significant improvement in all clinical scores was reported in both medial and lateral UKA patients. In medial UKA patients, male gender was associated with higher probability of better scores in overall KOOS, FJS-12 and in specific KOOS subscales. No other associations were reported between biometric parameters and outcome for either medial or lateral UKA. CONCLUSIONS: Robotic-assisted medial and lateral UKAs demonstrated satisfactory clinical outcomes and excellent survivorship at 3-year follow-up. Continued patient follow-up is needed to determine the long-term device performance and clinical satisfaction. LEVEL OF EVIDENCE: Retrospective cohort study, Level IV.

Arthroscopic posterior bone block: surgical technique.

Posterior glenohumeral instability remains a difficult problem. There are still many controversies regarding surgical treatment, due to a lack of understanding the pathomechanical issues leading to posterior instability. This article presents a new arthroscopic technique of posterior bone block augmentation, which we found to be effective, repeatable and successful. This technique can be used for combined soft tissue and bony defects as well as for revisions after previous soft tissue reconstructions.

Anterosuperior labral tear without biceps anchor involvement: a subtle isolated cause of a painful shoulder.

PURPOSE: The purposes of this study were to determine common clinical symptoms related to an anterosuperior labral tear without biceps anchor involvement and to establish the outcome of arthroscopic management of this injury. METHODS: In our database of arthroscopic procedures we identified 23 patients with an isolated anterosuperior labral tear. The mean age at the time of surgery was 38.3 ± 6.8 years (range, 18 to 59 years). The preoperative clinical diagnosis varied, but an anterosuperior labral isolated lesion was not detected before surgery. The diagnosis of anterosuperior labral tear was made arthroscopically, and the lesion was fixed with a suture anchor technique, by use of 1 single bioabsorbable anchor. Patients were reviewed after a minimum of 2.5 years of follow-up. Clinical outcome was evaluated with the Rowe score, American Shoulder and Elbow Surgeons score, Simple Shoulder Test score, and visual analog scale score. RESULTS: History, clinical examination, and preoperative imaging usually failed to indicate the presence of an isolated anterosuperior labral tear as the cause of shoulder pain in our patients. Repair of the labral lesions yielded good to excellent results with normalization of the range of motion and a significant improvement in shoulder scores (Rowe, American Shoulder and Elbow Surgeons, Simple Shoulder Test, and visual analog scale). CONCLUSIONS: Isolated tears of the anterosuperior labrum represent a subtle cause of shoulder pain and dysfunction. The lesion is very difficult to diagnose clinically. Arthroscopic repair is a reliable procedure providing a good outcome in terms of pain relief, patient satisfaction, and shoulder scores. LEVEL OF EVIDENCE: Level IV, therapeutic case series.

Posterior shoulder pain and anterior instability: a preliminary clinical study.

Different clinical tests have been suggested in the literature as significant indicators of anterior shoulder instability. Sometimes patients with recurrent anterior shoulder instability may show some muscular guarding thus making the evaluation of specific clinical tests very difficult. These patients may also report a medical history with posterior shoulder pain that can be also elicited during some clinical manoeuvres. From September 2005 to September 2006 we prospectively studied patients who underwent an arthroscopic anterior capsuloplasty. Shoulder clinical examination was performed including anterior shoulder instability tests (drawer, apprehension and relocation tests). Furthermore the exam was focused on the presence of scapular dyskinesia and posterior shoulder pain. The patients were also evaluated with ASES, Rowe, SST (Simple Shoulder Test), Constant and UCLA (University of California at Los Angeles) scoring system preoperatively and at the latest follow-up time. In the period of this study we observed 16 patients treated for anterior gleno-humeral arthroscopic stabilisation, who preoperatively complained also of a posterior scapular pain. The pain was referred at the level of lower trapezium and upper rhomboids tendon insertion on the medial border of the scapula. It was also reproducible upon local palpation by the examiner. Four of these patients also referred pain in the region of the insertion of the infraspinatus and teres minor. After arthroscopic stabilisation the shoulder was immobilised in a sling with the arm in the neutral rotation for a period of 4 weeks. A single physician supervised shoulder rehabilitation. After a mean time of 6.8 months of follow-up, all the shoulder scores were significantly improved and, moreover, at the same time the patients referred the disappearance of the posterior pain. Posterior scapular shoulder pain seems to be another complaint and sign that can be found in patients affected by anterior shoulder instability. It can also be related to eccentric work of posterior stabilising muscles of scapula during the altered biomechanics observed in case of anterior shoulder instability. This pain responds positively to surgical intervention showing that re-centring the humeral head probably also re-establishes the periscapular muscle-firing pattern with a mechanism mediated by the proprioceptive system.