Survivorship and Clinical Outcomes of Primary Total Knee Arthroplasty Performed in Patients 35 Years of Age and Younger

BACKGROUND

Total knee arthroplasties (TKAs) for patients aged ≤35 years are rare but necessary for patients who have diseases such as juvenile idiopathic arthritis, osteonecrosis, osteoarthritis, and rheumatoid arthritis. Few studies have examined the 10-year and 20-year survivorship and clinical outcomes of TKAs for young patients.

METHODS

A retrospective registry review identified 185 TKAs in 119 patients aged ≤ 35 years performed between 1985 and 2010 at a single institution. The primary outcome was implant survivorship free of revision. Patient-reported outcomes were assessed at 2 time points: 2011 to 2012 and 2018 to 2019. The average age was 26 years (range, 12 to 35). Mean follow-up was 17 years (range, 8 to 33).

RESULTS

Survivorship decreased from 84% (95% confidence interval [CI]: 79 to 90) at 5 years to 70% (95% CI: 64 to 77) at 10 years and to 37% (95% CI: 29 to 45) at 20 years. The most common reasons for revision were aseptic loosening (6%) and infection (4%). Risk factors for revision included increasing age at time of surgery (Hazards Ratio [HR] 1.3, P = .01) and use of constrained (HR 1.7, P = .05) or hinged prostheses (HR 4.3, P = .02). There were 86% of patients reporting that their surgery resulted in "a great improvement" or better.

CONCLUSION

Survivorship of TKAs in young patients is less favorable than expected. However, for the patients who responded to our surveys, TKA demonstrated substantial pain relief and improvement in function at 17-year follow-up. Revision risk increased with older age and higher levels of constraint.

Does Robotic-Assisted Total Hip Arthroplasty Improve Accuracy of Cup Positioning?

Acetabular component malpositioning is a frequent cause of complications in total hip arthroplasty including instability, increased wear, osteolysis, impingement, and revision surgery. Recently, robotics and navigation have been introduced to improve cup positioning in total hip arthroplasty. The purpose of this study was to compare the accuracy of postoperative acetabular component positioning using MAKO robotic-assisted versus manual acetabular component placement. A consecutive series of 100 total hip replacements were performed in 100 patients. The first 50 were performed using manual techniques, while the second 50 were performed using MAKO-guided acetabular component placement. Postoperative anteroposterior pelvis radiographs were used to determine the postoperative anteversion and inclination of the cup relative to the goal of 15 and 45°, respectively. In the manual group, the average anteversion and inclination was 14.3 and 44.2°, respectively, with 28% within 5° and 82% within 10° of the goal alignment, respectively. In the robotic group, the average anteversion and inclination was 15.1 and 45.6°, respectively, with 54 and 88% within 5 and 10° of the goal alignment, respectively. This equated to a statistically significant improvement in the number of acetabular components placed within 5° of the target alignment with the use of robotic guidance (p = 0.0142). From the authors' study, they were able to demonstrate a significant improvement in acetabular component alignment with the use of robotic techniques. Additional studies are needed to demonstrate improvement in clinical outcomes as a result of improved accuracy and precision of acetabular component placement.

Peer-to-Peer Collaboration Adds Value for Surgical Colleagues

BACKGROUND

Peer-to-peer advisory among colleagues in orthopedic surgery is commonplace in academic medical centers. In the private practice setting, however, it becomes more difficult for surgeons to discuss complex cases among peers.

PURPOSE/QUESTIONS

We sought to study the effect of peer-to-peer mentorship on surgeons' decision-making and on patient care across academic and private adult joint reconstruction practices via the use of group secured messages.

METHODS

From 2013 to 2016, we established a messaging system that was compliant with the Health Insurance Portability and Accountability Act (HIPAA) among five previous adult hip and knee reconstruction co-fellows in order to discuss complex cases. Data collected from each case included patient demographics (age and sex), history and physical examination, relevant imaging in orthogonal planes, and preliminary diagnosis and treatment plans. Data collected from group responses included nature of additional inquiries, literature citations, operative recommendations, and sample imaging of similar cases previously treated.

RESULTS

The group consisted of two private practice surgeons and three academic surgeons. Data was collected on 283 cases discussed during the study period. None of the patients had any HIPAA violations. The mean number of reviewers who commented on a case was 2.4, with at least one response in 97% of cases. In 33% of the cases, the peers confirmed the initial treatment plan, and in 67% of the cases, an alternative treatment plan was recommended and executed. The case distribution was 94 primary and 189 revision procedures, including 173 hips, 103 knees, three ankles, two shoulders, and two pelvises.

CONCLUSION

In the majority of cases exchanged between young surgeons via a group messaging system, a significant impact on patient care was appreciated. In a technology-driven era, peer-to-peer advisory for difficult cases via a rapid feedback method may allow for substantial improvement in patient care, particularly for surgeons not practicing at a large academic medical center with access to several partners and multiple opinions.

Results of Cemented vs Cementless Primary Total Knee Arthroplasty Using the Same Implant Design

BACKGROUND

Although cemented total knee arthroplasty (TKA) continues to be the gold standard, there are patient populations with higher failure rates with cemented TKAs such as the obese, morbidly obese, and younger active males. Cementless TKA usage continues to increase because of the potential benefits of long-term biologic fixation similar to the rise in cementless total hip arthroplasty. The purpose of this study was to evaluate the clinical and radiographic results of cementless TKA using a novel highly porous cementless tibial baseplate.

METHODS

This was a retrospective matched case-control study of 400 primary TKAs comparing cementless vs cemented TKAs using the same implant design (Stryker Triathlon; Stryker Inc, Mahwah, NJ). Two-hundred patients with a mean age of 64 years (range 42-88 years) and body mass index (BMI) of 33.9 kg/m² (range 19.7-57.1 kg/m²) were matched to 200 primary cemented TKA patients with a mean age of 64 years (range 43-87 years) and BMI of 33.1 kg/m² (range 22.2-53.2 kg/m²). The mean follow-up in the cementless group was 2.4 years (range 2-3.5 years) and in the cemented group was 5.3 years (range 2-10.9 years). Clinical and radiographic analyses were evaluated. Statistical analysis was performed using the Microsoft Excel, version 15.21.1.

RESULTS

There was no statistical difference in age, BMI, and preoperative Knee Society Scores between the 2 groups (P = .22, P = .82, and P = .43, respectively). Patients in both groups had a similar incidence of postoperative complications (P = .90). Cementless group had 7 revisions with one aseptic loosening of the tibial component (0.5%). Cementless tibial baseplates demonstrated areas of increased bone density at the pegs of the tibial baseplate. The cemented group had 8 total revisions with 5 cases of aseptic loosening (2.5%).

CONCLUSION

Early results of cementless TKA using a highly porous tibial baseplate designed with a keel and 4 pegs appear promising with one case of aseptic loosening at minimum 2-year follow-up. As the demographics of patients undergoing TKA change to include younger, obese, and more active patients, along with increased life expectancy, the use of a highly porous cementless tibial baseplate may be beneficial in providing long-term durable biologic fixation similar to the success of cementless total hip arthroplasty.

Revision total hip arthroplasty with modular femoral stems

As the rate of revision total hip arthroplasty (THA) rises, attention must be paid to potential complications relating to bone loss, soft tissue deficiencies, and loss of tissue planes. Using modular femoral stems in revision surgery allows for varying amounts of bone loss in the proximal and distal femur while letting the surgeon adjust rotation, leg length, and offset. We retrospectively reviewed 125 patients that underwent revision THA with a modular femoral component system and had minimum 2 year follow-up. Ten patients required reoperations for infection, recurrent dislocation, or fracture treatment. There was no evidence of radiographic loosening or mechanical failure in the remaining patients. Modular femoral components provide excellent intraoperative flexibility and significant radiographic and clinical benefits as seen in this patient cohort.

Midterm results of hybrid cement technique in revision total knee arthroplasty

While the number of revision total knee arthoplasties (TKA) performed in the United States continues to rise annually, controversy exists whether intramedullary stems should be cemented or press-fit. Retrospective analysis of midterm survivorship rate of revision TKA using hybrid stem fixation in 119 patients was performed. Revision was performed predominantly for aseptic loosening (78) and infections (28). Average follow-up was 62months (range, 46-80). Knee Society Pain and Function scores improved from 39 and 58 to 68 and 79 (P<.05). Fifty-eight tibial offsets and 28 femoral offsets were utilized. Three knees (2.5%) required revision without any cases of aseptic loosening. Radiographic complete or progressively advanced (>2mm) radiolucent lines were not observed in any patient. At mid-term follow-up, revision hybrid TKA provides excellent fixation with extremely low rates of aseptic loosening and avoids the inherent complications of extensive intramedullary cement.

Predictors of Oswestry Disability Index worsening after lumbar fusion

The authors identified patients with an increase in their Oswestry Disability Index (ODI) score after lumbar spine fusion to evaluate whether this is a plausible definition of deterioration and to determine whether any common patient characteristics exist.A total of 1054 patients who underwent lumbar spinal fusion and had 2-year follow-up data, including the Short Form 36, the ODI, and numeric rating scales for back and leg pain, were identified. Patients with worsening ODI were compared with the remaining cohort. Twenty-eight patients had an absolute increase (worse) in ODI at 1 year postoperatively. Participants with worsening ODI scores included 13 men and 15 women with an average age of 43.3 years; 15 (54%) were smokers. Common medical comorbidities included obesity and hypertension. Complications occurred in 5 (18%) patients and included wound infection, dural tear, and nerve root injury. Pseudarthrosis was common (n=8; 28%). Twenty-one patients required an additional intervention, including epidural injections, fusion revision, and cervical spine surgery.It is important to have a clear definition of deterioration to better provide informed consent or choice of treatment. Only 28 (2.6%) patients were identified as having an increase in ODI score at 2-year follow-up.