INSTABILITY AFTER TOTAL KNEE REPLACEMENT WITH A MOBILE-BEARING PROSTHESIS IN A PATIENT WITH MULTIPLE SCLEROSIS

Treatment of Postoperative Instability Following Total Knee Arthroplasty in Patients With Parkinson's Disease

Acute postoperative posterior total knee arthroplasty (TKA) dislocation is rare in primary surgery but has been associated with Parkinson's disease (PD). We present a 77-year-old woman with knee arthritis and PD who sustained an acute, recurrent TKA posterior dislocation, recalcitrant to polyethylene upsizing. Transient stability was obtained for a period of 1 year after postoperative hamstring injection with botulinum toxin A and short-term immobilization. Spontaneous instability recurred after 1 year, and stability was obtained with revision to a more constrained construct and has been monitored over a period of 2 years. This is the first report demonstrating the use of botulinum toxin A for acute posterior TKA instability associated with PD. We endorse the necessity of increased constraint to maintain long-term stability in patients with Parkinson's disease.

Multiple sclerosis is associated with adverse outcomes following hip and knee arthroplasty: A systematic review and meta-analysis of observational studies

BACKGROUND

The association of multiple sclerosis (MS) with joint diseases has been established. However, the impact of MS on postoperative outcomes following total joint arthroplasty (TJA) remains controversial. Therefore, a systematic review of the literature is warranted to ascertain the relationship between MS and adverse outcomes post-TJA.

METHODS

A systematic literature search of PubMed, Embase, Scopus, and the Cochrane Library from inception to 1 March 2023 was conducted to identify observational studies comparing post-TJA outcomes in MS and non-MS patients. Two investigators independently screened titles, abstracts, and full-text articles for eligibility. A random-effects model was used to calculate odds ratios (OR), mean differences (MD), and corresponding 95% confidence intervals (CI).

RESULTS

Seven retrospective cohort studies published between 2018 and 2022 met the inclusion criteria. Patients with MS had a higher risk of medical, surgical, and overall complications than patients without MS. Similarly, the MS group was more likely to experience an extended hospital stay, non-home discharge, and revision surgery compared to the control group. Joint infection and implant instability were also more common in patients with MS.

CONCLUSION

Although TJA may benefit MS patients, current evidence suggests that their postoperative outcomes may be inferior to those of non-MS patients. Thus, orthopaedic surgeons should inform MS patients of potential risks and perform preoperative optimization individually when considering elective arthroplasty.

A Systematic Review of Total Knee Arthroplasty in Neurologic Conditions: Survivorship, Complications, and Surgical Considerations

BACKGROUND

Patients with neurologic disorders present a unique set of challenges for knee surgeons because of contractures, muscle weakness, spasticity, and ligament instability. The primary purpose of this review was to report the outcomes of total knee arthroplasty (TKA) in these patients, including survivorship, complications, and surgical considerations.

METHODS

We performed a systematic review of articles using PubMed, Cochrane Central, EMBASE, and Google Scholar. All studies reporting outcomes of TKA in patients with Parkinson disease, multiple sclerosis, poliomyelitis, Charcot joint, spina bifida, stroke, and cerebral palsy were included.

RESULTS

In total 38 studies were included: 22 studies (461 patients) reported patient-reported outcome measures and 24 studies (510 patients) reported survivorship. All 38 studies reported complication rates. TKA resulted in an improvement in functional outcome in all series. Complication rate was higher in patients with neurologic conditions. Of studies reporting survivorship, mean follow-up ranged from 1 to 12 years with survivorship from 66% to 100%. All levels of implant constraint were reported without consensus. Limited rehabilitative data exist.

CONCLUSION

TKA in patients with neurologic disorders improves symptoms and function but carries significant risk. This review helps surgeons preoperatively counsel their patients in an informed manner. Careful planning, perioperative care, and appropriate implant selection may mitigate risk of complication.

Inhospital Complications of Patients With Neuromuscular Disorders Undergoing Total Joint Arthroplasty

INTRODUCTION

Orthopaedic surgeons are wary of patients with neuromuscular (NM) diseases as a result of perceived poor outcomes and lack of data regarding complication risks. We determined the prevalence of patients with NM disease undergoing total joint arthroplasty (TJA) and characterized its relationship with in-hospital complications, prolonged length of stay, and total charges.

METHODS

Data from the Nationwide Inpatient Sample from 2005 to 2014 was used for this retrospective cohort study to identify 8,028,435 discharges with total joint arthroplasty. International Classification of Diseases, Ninth Revision, Clinical Modification codes were used to identify 91,420 patients who had discharge diagnoses for any of the NM disorders of interest: Parkinson disease, multiple sclerosis, cerebral palsy, cerebrovascular disease resulting in lower extremity paralysis, myotonic dystrophy, myasthenia gravis, myositis (dermatomyositis, polymyositis, and inclusion-body myositis), spinal muscular atrophy type III, poliomyelitis, spinal cord injury, and amyotrophic lateral sclerosis. Logistic regression was used to estimate the association between NM disease and perioperative outcomes, including inpatient adverse events, length of stay, mortality, and hospital charges adjusted for demographic, hospital, and clinical characteristics.

RESULTS

NM patients undergoing TJA had increased odds of total surgical complications (odds ratio [OR] = 1.21; 95% confidence interval [CI], 1.17 to 1.25; P < 0.0001), medical complications (OR = 1.41; 95% CI, 1.36 to 1.46; P < 0.0001), and overall complications (OR = 1.32; 95% CI, 1.28 to 1.36; P < 0.0001) compared with non-NM patients. Specifically, NM patients had increased odds of prosthetic complications (OR = 1.09; 95% CI, 0.84 to 1.42; P = 0.003), wound dehiscence (OR = 5.00; 95% CI, 1.57 to 15.94; P = 0.0002), acute postoperative anemia (OR = 1.20; 95% CI, 1.16 to 1.24; P < 0.0001), altered mental status (OR = 2.59; 95% CI, 2.24 to 2.99; P < 0.0001), urinary tract infection (OR = 1.45; 95% CI, 1.34 to 1.56; P < 0.0001), and deep vein thrombosis (OR = 1.27; 95% CI, 1.02 to 1.58; P = 0.021). No difference of in-hospital mortality was observed (P = 0.155).

DISCUSSION

Because more patients with NM disease become candidates of TJA, a team of neurologists, anesthesiologists, therapists, and orthopaedic surgeon is required to anticipate, prevent, and manage potential complications identified in this study.

LEVEL OF EVIDENCE

Level III, retrospective cohort study.

Defining Treatment Success After 2-Stage Exchange Arthroplasty for Periprosthetic Joint Infection

BACKGROUND

Two-stage exchange arthroplasty remains the preferred surgical treatment method for patients with chronic periprosthetic joint infection (PJI). The success of this procedure is not known exactly as various definitions of success have been used. This study aimed at analyzing the difference in outcome following 2-stage exchange arthroplasty using different definitions for success.

METHODS

A retrospective study of 703 patients with PJI who underwent resection arthroplasty and spacer insertion between January 1999 and June 2015 was performed. Chart review identified intraoperative cultures at the time of spacer, reimplantation, and any subsequent reinfections or surgeries following spacer insertion. After applying the exclusion criteria, a total of 570 patients were included in the analysis. Five definitions of treatment success were assessed: (1) Delphi consensus success, (2) modified Delphi consensus success, (3) microbiological success, (4) implant success, and (5) surgical success.

RESULTS

Of the 570 patients with PJIs, 458 were reimplanted at a mean of 4.1 months. Mortality was 13.9% with 6.7% occurring before reimplantation. Treatment success was highly variable depending on the definition used (54.2%-88.9%). In 19.6% of PJI cases, the Delphi consensus definition could not be assessed as reimplantation never occurred. Furthermore, 67.0% of these patients underwent reoperations, which may not be accounted for in the Delphi consensus definition.

CONCLUSION

Treatment success rates vary dramatically depending on the definition used at our institution. We hope these definitions can help bring forth awareness for standardized reporting of outcomes, but further validation and agreement of these definitions among surgeons and infectious disease physicians is crucial.

Total Hip and Knee Arthroplasty in Patients with Multiple Sclerosis

Background

Hip and knee replacements for osteoarthritis are established procedures for improving joint pain and function, yet their safety in patients with multiple sclerosis (MS) is unknown. Patients with MS face unique surgical challenges due to underlying neurologic dysfunction. Current literature on arthroplasty in MS is limited to case reports focusing on adverse events.

Methods

Of 40 identified patients who underwent hip or knee replacement, 30 had sufficient data for inclusion. We reviewed their medical records and recorded reasons for surgery, age at surgery, MS characteristics, surgical complications, and ambulatory aid status before and after surgery. We supplemented medical record review with questionnaires regarding preoperative and postoperative pain and satisfaction with surgical outcomes.

Results

Median follow-up was 26 months. Complications of surgery were reported in ten patients (33%), mostly mild and self-limited, although four patients (13%) required repeated operation. Six patients (20%) reported improvements in ambulatory aid use compared with presurgery baseline, ten (33%) worsened, and 14 (47%) were unchanged. In 20 patients who completed the questionnaire, mean ± SD joint pain scores (on 0-10 scale) decreased from 8.6 ± 2.0 preoperatively to 2.9 ± 2.4 postoperatively (P < .001). Five patients (25%) were free of joint pain at last follow-up.

Conclusions

These results suggest that pain reduction is a realistic outcome of total knee or hip arthroplasty in people with MS and that improved functional gait outcomes are possible in some patients. Prospective, multicenter, collaborative studies are needed to optimize selection and improve outcomes in people with MS considering arthroplasty.

Survivorship and Outcomes in Patients With Multiple Sclerosis Undergoing Total Joint Arthroplasty

BACKGROUND

Patients with multiple sclerosis (MS) frequently require total joint arthroplasty (TJA). The outcomes of TJA in patients with MS, who are frequently on immunomodulatory medications and physically deconditioned, remain largely unknown. The aim of this study is to elucidate the survivorship and reasons for failure in this patient population.

METHODS

A single-institution retrospective review of 108 TJAs (46 knees and 62 hips) was performed from 2000 to 2016. An electronic chart query based on MS medications and International Classification of Diseases, Ninth Revision codes was used to identify this population followed by a manual review to confirm the diagnosis. Outcomes were then assessed using revision for any reason as the primary end point. Functional outcomes were assessed using Short Form 12 scores. Survivorship curves were generated using the Kaplan-Meier method.

RESULTS

At an average follow-up of 6.2 years, 19.4% (21/108) of patients required a revision surgery. Instability (5.6%, P = .0278) and periprosthetic joint infection (4.6%, P = .0757) were among the most common reasons for revision. The overall survivorship of TJA at years 2, 5, and 7, respectively, was 96.5% (95% confidence interval [CI], 92.6-100), 86.3% (95% CI, 77.7-94.5), and 75.3% (95% CI, 63.5-87.0). Functional score improvement was less in MS cohort than patients without MS.

CONCLUSION

Patients with MS are at increased risk of complications, particularly instability and periprosthetic joint infection. Despite this increased risk of complications, patients with MS can demonstrate improved functional outcomes, but not as much as patients without MS. Patients with MS should be counseled appropriately before undergoing TJA.

Tibiofemoral Dislocation After Total Knee Arthroplasty

BACKGROUND

Tibiofemoral dislocation after total knee arthroplasty (TKA) is a rare complication. Published case reports describe fewer than 6 patients, making conclusions about the etiology, epidemiology, complications, and treatment of tibiofemoral dislocation difficult. This case series highlights common demographic features, potential causes, and difficulties during the management of tibiofemoral dislocations after TKA.

METHODS

Between 2005 and 2014, 14 patients presented to our institution with a tibiofemoral dislocation. Patients were excluded if they had patellofemoral dislocation or subluxation without a tibiofemoral dislocation. We retrospectively reviewed patient demographics, time to first dislocation, number of dislocations, time to surgical intervention, complications, and potential etiologies of tibiofemoral dislocation.

RESULTS

Twelve of 14 patients were female. Their mean body mass index was 33 ± 10 kg/m(2). Thirteen of 14 patients had a mean of 2.0 ± 1.4 dislocations. Four patients dislocated due to polyethylene damage and 5 due to ligamentous incompetence. Twelve of 14 patients required open surgical intervention. Complications in this patient population were common with 3 cases of infection, 7 cases of multiple dislocation, 2 cases of popliteal artery laceration, 1 case receiving a fusion, and 1 case receiving an amputation.

CONCLUSION

Patients with tibiofemoral dislocation after TKA are predominantly obese, female, and have a high risk for complications. They dislocate predominantly because of polyethylene damage or ligamentous incompetence. Re-dislocation is common if treated with closed reduction alone.

Total knee arthroplasty in multiple sclerosis

We present a case report of total knee arthroplasty complicated by spasticity and contractures in a patient with multiple sclerosis (MS). Four previous case reports in the literature describe adverse outcomes after total knee arthroplasty in persons with MS secondary to severe spasticity. Preoperative, intraoperative, and postoperative considerations for persons with MS, which may help to improve functional outcomes, are discussed. Prospective research is needed among persons with MS to help determine the timing and selection of persons for arthroplasty and to minimize complications related to spasticity.

Mobile bearing or fixed bearing? A meta-analysis of outcomes comparing mobile bearing and fixed bearing bilateral total knee replacements

BACKGROUND

To compare outcomes between mobile-bearing (MB) and fixed-bearing (FB) in bilateral total knee replacements.

METHODS

The MEDLINE, EMBASE and Cochrane Library databases were searched. Randomized controlled trials of bilateral total knee arthroplasty with one of each design implanted were identified. Weighted mean differences (WMDs) and pooled risk ratios (RRs) were calculated using fixed- or random-effects models.

RESULTS

Twelve studies were identified with a total of 807 patients and 1614 knees. All RCTs were of high quality with a low risk of bias. No statistical difference was found between MB and FB at 2- to 5-year follow-up in terms of America Knee Society score (WMD: -1.29, 95% CI: -5.65 to 3.06), pain score (WMD: -3.26, 95% CI: -10.45 to 3.93), range of motion (WMD: -4.16, 95% CI: -9.97 to 1.66), reoperation (RR: 1.00, 95% CI: 0.28 to 3.60), and radiolucent lines (RR: 1.51, 95% CI: 0.70 to 3.24). The results were similar at 1-, 5- to 8-, or >8-year follow-up. Patient's satisfaction (RR: 0.85, 95% CI: 0.54 to 1.34), and complication (≤2-year, RR: 0.55, 95% CI: 0.29 to 1.04; >2-year, RR: 1.0, 95% CI=0.73 to 1.38) also showed no difference between two groups.

CONCLUSIONS

Based on this meta-analysis we are unable to detect the superiority of MB as compared to FB. More randomized trials with a larger sample size and longer follow-up are needed to evaluate these two kinds of prosthesis.

LEVEL OF EVIDENCE

Therapeutic Level II.

Spontaneous dislocation of a mobile-bearing polyethylene insert after posterior-stabilized rotating platform total knee arthroplasty: a case report

We describe a dislocation after Scorpio mobile-bearing total knee arthroplasty. This system is a rotating platform posterior-stabilized design and utilizes a single post as part of the metal tibial tray. Only one locking ring inside the socket of the polyethylene insert secures a tight connection with the post. Spontaneous dislocation between the polyethylene insert and the metal tray occurred at 22 months post surgery while rising from the supine position with slight knee flexion. Operative findings revealed failure of the locking ring and the original insert was replaced with a thicker insert. Our case and a duplicated saw bone model demonstrated that failure of the locking system resulted in the dislocation of the insert.

Recurrent total knee arthroplasty dislocation after dorsal meningioma diagnosed

We report on a 68-year-old woman with gonarthrosis who underwent total knee arthroplasty. Having initially achieved a satisfactory result, she developed at 5 months postoperation an irreducible flexion contracture necessitating revision surgery; but no pathological findings were discovered. In the immediate postoperative period, the patient developed a severe spasm of the hamstring muscles and a paralysis of the external popliteal sciatic nerve with a posterior dislocation of the knee. After reduction, an electromyography study showed an alteration in medullary sensitive conduction; and the magnetic resonance image showed a lesion compatible with meningioma. This complication has not been previously described as a consequence of spinal tumor. Technical considerations are described for this rare complication, which remains a serious challenge for the orthopedic surgeon.

Dislocation following total knee arthroplasty: A report of six cases

BACKGROUND

Dislocation following total knee arthroplasty (TKA) is the worst form of instability. The incidence is from 0.15 to 0.5%. We report six cases of TKA dislocation and analyze the patterns of dislocation and the factors related to each of them.

MATERIALS AND METHODS

Six patients with dislocation of knee following TKA are reported. The causes for the dislocations were an imbalance of the flexion gap (n=4), an inadequate selection of implants (n=1), malrotation of components (n=1) leading to incompetence of the extensor mechanism, or rupture of the medial collateral ligament (MCC). The patients presented complained of pain, giving way episodes, joint effusion and difficulty in climbing stairs. Five patients suffered posterior dislocation while one anterior dislocation. An urgent closed reduction of dislocation was performed under general anaesthesia in all patients. All patients were operated for residual instability by revision arthroplasty after a period of conservative treatment.

RESULTS

One patient had deep infection and knee was arthrodesed. Two patients have a minimal residual lag for active extension, including a patient with a previous patellectomy. Result was considered excellent or good in four cases and fair in one, without residual instability. Five out of six patients in our series had a cruciate retaining (CR) TKA designs: four were revised to a posterior stabilized (PS) TKA and one to a rotating hinge design because of the presence of a ruptured MCL.

CONCLUSION

Further episodes of dislocation or instability will be prevented by identifying and treating major causes of instability. The increase in the level of constraint and correction of previous technical mistakes is mandatory.

Non-traumatic anterior dislocation of a total knee replacement associated with neurovascular injury

Prosthetic total knee replacements rarely dislocate. When dislocation does occur, it is usually in a posterior direction in association with a posterior stabilised, cruciate-sacrificing prosthesis. Neurovascular injury is unusual. In this report, we describe a case of anterior dislocation of a cruciate-retaining total knee replacement in a 67-year-old woman. The dislocation occurred in the absence of overt trauma and resulted in severe neurovascular injury.

Staged bilateral mobile-bearing and fixed-bearing total knee arthroplasty in the same patients: a prospective comparison of a posterior-stabilized prosthesis

Mobile-bearing total knee arthroplasty (TKA) has several theoretical advantages over fixed-bearing TKA. We conducted a prospective randomized trial to compare the results of mobile-bearing and fixed-bearing posterior-stabilized TKA in the same patients using the same femoral component design of a mobile-bearing prosthesis in one knee and a fixed-bearing prosthesis in the other knee in 25 patients with osteoarthritis. The mean follow-up was 40 months. No significant differences were found in the mobile-bearing and fixed-bearing knees in terms of clinical and radiographic results. No osteolysis, loosening, or revision occurred. One knee with a mobile-bearing prosthesis had a dislocation of the rotating bearing; however, spontaneous reduction occurred and the dislocation did not recur. Satisfactory early results can be achieved in both mobile-bearing and fixed-bearing knees. We could not demonstrate an advantage of a mobile-bearing TKA.

Multiple sclerosis and bilateral dislocations of total knee replacements: a case report

We report on a 67-year-old lady with multiple sclerosis (MS) who underwent bilateral total knee replacements using a fixed bearing posterior cruciate retaining prosthesis. Having initially achieved a satisfactory result, she developed recurrent dislocations of both knees necessitating bilateral revision surgery. Such complications are not previously described as a sequela of a neurological disease.

Von der tibiofemoralen Instabilität zur Luxation in der Knieendoprothetik

Tibiofemoral instability is increasingly recognized as a mode of failure in total knee arthroplasty (TKA). Severe instability may lead to dislocation. Wrong surgical technique and wrong choice of constraint of the prostheses are the main causes for instability. Malalignment, malrotation and intraoperatively uncorrected instability especially in flexion may lead to an unstable total knee arthroplasty. Cruciate-retaining designs and mobile platforms can be considered only in the presence of well-balanced ligaments. Cruciate-substituting designs give more stability and many people find them more forgiving. However, correction of varus-valgus instability and severe flexion laxity cannot be provided. Varus-valgus contrained designs cannot compensate for the absence of medial and lateral collateral ligaments. Such cases are most reliably treated with a linked implant (rotating hinge). The exact analysis of the cause of an unstable or dislocated total knee arthroplasty represents the most essential basis of a successful treatment. Exchange of the prostheses represents the most successful procedure. Correction of implantation failures should be performed. A more constrained design should be used if insufficient ligaments are found. Post-traumatic instability or dislocation represents an exception.

Dislocation of posterior-stabilized mobile-bearing knee prosthesis. A case report

Spin-out of mobile-bearing knees is a significant early complication of mobile-bearing total knee arthroplasty. Dislocation of the cam-post mechanism of fixed-bearing posterior-stabilized knees occurs more rarely. We have observed an unusual case of dislocation of posterior-stabilized rotating-platform total knee arthroplasty, which has both a cam-post mechanism and rotating platform. A 65-year-old man with knee osteoarthritis and cervical spondylotic myelopathy underwent total knee arthroplasty using a mobile-bearing prosthesis. The dislocation, which occurred 4 days postoperatively, could not be reduced by closed manipulation. However, spontaneous reduction occurred 6 days after the dislocation, which did not recur. A gap mismatch or trapezoidal-shaped gaps may lead to dislocation or spin-out of the bearing insert. This case illustrates that dislocation of a posterior-stabilized mobile-bearing total knee arthroplasty can occur, and both quadriceps deficiency and ligament laxity may contribute to the risk of dislocation.