Ipsilateral Total Knee Arthroplasty Research Articles

Periprosthetic Hip and Knee Infection: Is an Ipsilateral Uninfected Total Joint Arthroplasty at Risk?

BackgroundPeriprosthetic joint infections (PJIs) of total hip arthroplasty (THA) or total knee arthroplasty (TKA) may occur in the setting of an uninfected ipsilateral prosthetic joint. However, the risk to that uninfected ipsilateral joint is unknown. We analyzed the survivorship free from PJI in at risk THAs and TKAs following treatment of an ipsilateral knee or hip PJI, respectively. MethodsUsing our institutional total joint registry, we identified 205 patients who underwent treatment for PJI (123 THAs and 83 TKAs) with an at-risk ipsilateral in situ knee or hip, respectively, between 2000 and 2019. In total, 54% of index PJIs were chronic and 46% were acute. The mean age was 70 years, 47% were female, and the mean body mass index was 32. Kaplan-Meier survivorship analyses were performed. Mean follow-up was 6 years. ResultsThe 5-year survivorship free of PJI in an at-risk THA after an ipsilateral TKA was treated for PJI was 97%. The 5-year survivorship free of PJI in an at-risk TKA when the ipsilateral THA was treated for PJI was 99%. Three PJIs occurred (2 THAs and 1 TKA), all over 1 year from the index ipsilateral PJI treatment. One hip PJI was an acute hematogenous infection that resulted from pneumonia. The other 2 new PJIs were caused by the same organism as the index PJI and were due to a failure of source control at the index joint. ConclusionsWhen diagnosed with PJI in a single joint, the risk of developing PJI in an ipsilateral prosthetic joint within 5 years was low (1 to 3% risk). In the rare event of an ipsilateral infection, all occurred greater than one year from the index PJI and 2 of 3 were with the same organism when source infection control failed. Level of EvidencePrognostic Level III.

Total Knee Arthroplasty in Patients with Ipsilateral Hip Fusion: Technical Notes and Literature Review.

Numerous studies report the success and outcomes of the total knee arthroplasty (TKA); however, few papers present patients with knee osteoarthritis and ipsilateral hip fusion. One controversy when treating patients requiring a TKA with prior ipsilateral hip fusion is whether to first perform a total hip arthroplasty (THA) of the fused hip, followed by the ipsilateral TKA, or to proceed with the TKA without replacing the hip; studies suggest that the position of the fused hip is a key factor when making this therapeutical decision. In addition, performing a TKA in patients with an ipsilateral fused hip may require modifications to the surgical technique generated by the lack of joint mobility in the hip. We identified 12 studies encompassing 30 patients with hip fusion and ipsilateral TKA in current orthopedic literature, but only six offered insights on patient positioning on the operating table during surgery. This study aims to review the current literature on patients with knee osteoarthritis and prior ipsilateral hip fusion and to present some technical considerations when performing a TKA on a 75-year-old patient with hip ankylosis who underwent a total ipsilateral knee arthroplasty in our clinic.

Paper 32: Meniscus Repair Outcomes and Reoperation Rate in Patients Over the Age of 40

Objectives: Meniscus injuries remain a common source of morbidity in patients over the age of 40. Historically, meniscus injuries in this age group have been treated non-operatively or with surgical management limited to debridement procedures. There is strong evidence for repair over meniscectomy in younger patients, however literature remains sparce regarding repair outcomes and re-operation rates for patients over the age of 40. The objectives of this study were to document patient reported outcomes, complications, and re-operation rates for meniscus repairs in patients above the age of 40 and determine what patient demographics or injury characteristics correlated with reoperation. Methods: A retrospective chart review was conducted at a single academic institution after obtaining IRB approval. An initial query of patients over the age of 40, was performed via the CPT code 29882. Inclusion criteria consisted of patient age greater than 40 at time of initial meniscal repair. Exclusion criteria consisted of prior surgery in the ipsilateral knee, meniscal root repair, septic arthritis postoperatively, and any form of knee trauma postoperatively. Patients that met inclusion criteria were chart reviewed for relevant data including demographic information, comorbidities, surgical procedure information such as type of implant used, laterality of meniscus tear, type of tear and pattern, and revision/re-operation data. Patients were then contacted to answer full 100-point KOOS (Knee Injury and Osteoarthritis Outcome Score) questionnaires. Results: 413 total patients met inclusion criteria. The average age at time of surgery was 46 years (IQR, 43-51), and 214 patients were female (51.8%). KOOS scores were reported at a median follow-up of 24-months (IQR, 3-62). Median symptom, pain, activity of daily living (ADL), sport, and quality of life (QoL) subscales were reported as 78.6 (IQR, 60.7-92.9), 87.5 (IQR, 69.4-97.2), 94.1 (IQR, 82-100), 80.0 (IQR, 55-95), and 68.8 (IQR, 40.6-81.3), respectively. A total of 74 patients underwent reoperation (17.8%). There was no significant difference in reoperation rates when stratified by age group (40-49, 50-59, 60-69) (p=0.515). Reoperation rates were not affected by type of implant used for initial meniscus repair (Fast-fix anchor, Omnispan meniscal anchor, Meniscal cinch implant, Fiberwire, MaxBraid suture, Ethibond suture, PDS suture or Bionics meniscal arrow) (p>0.7). Average number of all-inside anchors used for repair was 2 (IQR, 2-3) and did not correlate with reoperation (p=0.49). Location of initial meniscus tear (body or posterior horn) and tear pattern did not correlate with reoperation rates (p>0.36, p>0.28 respectively). A total of 47 patients complained of postoperative stiffness, of which 28 (6.7%) underwent lysis of adhesions and/or arthroscopic debridement (p=.042). Twenty-five patients sustained a meniscal re-tear or injury, of which 17 underwent reoperation with partial or total meniscectomy. Of the total patient cohort, only seven patients ultimately went on to require ipsilateral total knee arthroplasty (1.6%). Conclusions: Patients over the age of 40 who underwent meniscus repair showed favorable reported outcomes at a mean 2-year follow-up. Reoperation rates were associated with postoperative stiffness and repeat injury. Re-operation rates in patients over 40 are comparable to reported rates of younger patients who undergo meniscus repair.

Ipsilateral Concurrent Knee Arthroplasty and Tibial Osteotomy with 3D-Printed Patient-Specific Instrumentation: A Case Report.

A 70-year-old woman presented with knee pain and instability and was diagnosed with advanced knee osteoarthritis and bifocal tibial deformities. The complexity of the case challenged our team to perform a significant sagittal correction (>60°) and restore her ability to walk independently. We performed ipsilateral total knee arthroplasty and anterior closed wedge tibial osteotomy using virtual planning and 3D-printed patient-specific instrumentation. Using 2 separate 3D-printed patient-specific cutting guides for this patient with a complex deformity and managing the whole planning process in close collaboration between the surgeons and engineers resulted in a satisfactory postoperative outcome, optimal implant positioning and leg alignment, and minimal soft-tissue damage.

Outcomes of surgical management of closed periprosthetic distal femur fractures above total knee arthroplasties: A case series

Periprosthetic distal femur fractures present difficult treatment challenges and are expected to become more prevalent as the number of total knee arthroplasties (TKAs) continues to rise. The purpose of this study is to determine the functional outcomes and rate of re-operation following surgical treatment of closed distal femoral periprosthetic fractures above a TKA. We performed a retrospective review of 56 patients(45 females) who underwent surgical management of distal femur fractures (AO/OTA 33) above an ipsilateral TKA with a mean follow-up of 21 months (range, 12-78 months). Forty-three (77%) patients were treated with a lateral plate and screw construct, and 13 (23%) patients were treated with a retrograde intramedullary nail. There were 2 (4%) deep infections at a mean of 6 months (range, 5-7 months) post-operatively. At final follow-up, TKA components were retained in 53 (93%) patients, demonstrating a survivorship free of component revision following fracture treatment of 93% at 6.5 years. Survivorship free of any re-operation following fracture treatment was 86% at 6.5 years. Mean anatomic lateral distal femoral angle (aLDFA) was 84° (range, 72-89°) and mean anatomic posterior distal femoral angle (aPDFA) was 83° (range, 67-89°). There were 8 nonunions (14%) at 6 month follow-up, and no patients underwent a re-operation for malunion. This case series demonstrates increased revision rates and decreased survivorship of TKA components after surgical management of periprosthetic distal femur fractures. Surgeons must be aware of these potential complications when treating patients with periprosthetic distal femur fractures and counsel their patients appropriately. Therapeutic Level IV. See instructions for all others for a complete description of levels of evidence. • Closed distal femur fractures about a TKA demonstrate a high rate of non-union, 14% at 6-month follow-up. • Following this injury, patients experienced reduced mobility with only 82% being ambulatory after fixation, with 16% still wheelchair bound at 6 months after surgery. • As the number of annual TKA continues to rise, injuries involving those prosthetics will continue to rise.

Preoperative and Intraoperative Considerations Using Intramedullary Nails for the Treatment of Tibial Shaft Fractures Below Total Knee Arthroplasty.

Periprosthetic tibial shaft fractures below total knee arthroplasty (TKA) are relatively rare, with an incidence of approximately 1%. However, as the rates of arthroplasty increase, orthopaedic surgeons are likely to see a corresponding increase in these types of fractures. Native tibial shaft fractures are routinely treated with either nails or plates, and the success of intramedullary nailing of tibial shaft fractures has been well described in the literature. In this article, we seek to describe a case series of tibial shaft fractures in patients with ipsilateral TKA treated with infrapatellar intramedullary nailing. We will focus on preoperative considerations including templating and measurement of the anterior cortical implant distance on the lateral radiograph to ensure space for safe nail passage. We will also discuss intraoperative technical tricks, including Kirschner wire insertion for sounding the start point, utilization of the curved awl, use of hand reamers, and rotation of the nail to bypass the implant. Using meticulous preoperative planning and technical intraoperative tricks, patients with tibial shaft fractures below TKA may be successfully treated with intramedullary nailing.

Total Knee Arthroplasty following Knee Arthroscopy in Patients over 50.

The purpose of this study was to evaluate the conversion rate of knee arthroscopy to ipsilateral total knee arthroplasty (TKA) within 2 years in patients aged 50 or older at the time of arthroscopy. The administrative database from a large, physician-owned orthopaedic practice (>100 surgeons) was queried to identify patients over the age of 50 who had undergone arthroscopic knee surgery between January 1, 2006 and January 2, 2015. The subset of patients who converted to TKA within 2 years after knee arthroscopy was identified and matched by age and sex to a control population that did not convert to TKA. Rates of conversion to TKA were calculated. Prearthroscopic digital radiographs were reviewed and Kellgren-Lawrence (KL) grades were compared among case and control populations. Univariable analyses and multivariable regression analysis were performed. Eight hundred seven of 16,061 (5.02%) patients aged 50 or older were converted to TKA within 2 years following ipsilateral knee arthroscopy. In univariable analysis, the rate of conversion to TKA in patients aged between 50 and 54 was 2.94%, compared with 4.44% in patients aged between 55 and 64, and 8.32% in patients 65 or older (p < 0.0001). Female sex was associated with a higher rate of conversion to TKA in univariable analysis (5.93 vs. 4.02% in males, p < 0.0001). KL grades were higher among patients who converted to TKA compared with those who did not (p < 0.0001). In a multivariable regression model controlling for age, sex, and KL grade, only increased KL grade was associated with increased odds of conversion to TKA. In the appropriately selected older patient, the risk of conversion to TKA within 2 years of knee arthroscopy is low (∼5%). Patients with KL grade 2 or higher at the time of arthroscopy should be counseled on the increased odds of early conversion to TKA.

Periprosthetic femoral fracture type and location are influenced by the presence of an ipsilateral knee arthroplasty implant: A case-control study of 84 interprosthetic femoral fractures

BackgroundThis multicentre case-control study compares Vancouver Classification System (VCS) grade and Arbeitsgemeinschaft für Osteosynthesefragen/Orthopaedic Trauma Association (AO/OTA) fracture type in interprosthetic femoral fractures (IPFFs) between primary total hip arthroplasty (THA) and ipsilateral total knee arthroplasty (TKA) to periprosthetic femoral fracture (PFF) without ipsilateral TKA. MethodsData were collected following institutional approval. Eighty-four IPFFs were assessed for VCS grade and AO/OTA type. Each IPFF case (84) was matched to five PFF controls (360) by age, gender and stem fixation philosophy (SMD<0.1). VCS grade and AO/OTA type were compared between the IPFF and PFF groups using weighted proportions and medians. ResultsMedian (IQR) age of IPFF patients was 81.75 (76.57–85.33) years and 61 (72.6%) were female. The commonest VCS grade was B1 (34, 40.5%). The commonest AO/OTA type was spiral (51.8% of VCS B fractures; 50.0% of VCS C fractures). A greater proportion of fractures occurred distal to the stem in IPFF patients versus PFF patients (33.3% versus 18.2%, p = 0.003). VCS grade was significantly different between groups (p = 0.015). For VCS C fractures, twice as many AO/OTA transverse and wedge fractures occurred in the IPFF group compared to the PFF group (25.0% versus 12.6% and 7.1% versus 3.3%, respectively) although the overall difference was not statistically significant (p = 0.407). ConclusionThe presence of an ipsilateral TKA affects the location of PFF with more fractures occurring distal to the stem. A greater proportion of bending type fractures occurred when an ipsilateral TKA was present. These unstable fractures often require more complex surgery.

Mid-long-term results of total knee arthroplasty followed by ipsilateral total hip arthroplasty versus total hip arthroplasty subsequent to ipsilateral total knee arthroplasty: a case-control analysis

BackgroundThe aim of the present study was to compare the outcomes of patients who underwent different sequences of ipsilateral total hip arthroplasty (THA) and total knee arthroplasty (TKA).MethodsWe retrospectively identified 47 patients who underwent TKA followed by ipsilateral THA (THA-TKA) and 36 patients who received THA subsequent to ipsilateral TKA (TKA-THA) for rheumatoid arthritis or osteoarthritis between January 2008 and April 2014. Twenty-eight patients were selected for each group after case-control matching with preoperative demographics and protheses of THA. Clinical scores, radiographic results, complication rates, and survivorship were compared. The median duration of follow-up was 110 (range 80–149) months.ResultsBoth groups showed significant improvement in Harris Hip Scores, Knee Society Score, and Short Form-12 at the last follow-up compared to baseline (p < .001). At the last follow-up, all clinical scores were actually lower in the THA-TKA group, but those differences were not statistically significant. Otherwise, there was no significant difference in radiological alignment or complication rates. The survivorship of THA and TKA in the THA-TKA group was 94.7 and 95.7%, respectively, compared with 92.4 and 100.0% in the TKA-THA group at 8 years (log rank, p = .939 and .187).ConclusionsPatients who underwent ipsilateral THA and TKA with different sequences achieved similar favorable outcomes. Total joint arthroplasty can be performed safely with excellent outcomes in patients with a history of prior ipsilateral THA or TKA.Trial registrationThe trial was registered in the Chinese Clinical Trial Registry (ChiCTR2000035147) dated 2 August 2020.

Calcaneal insufficiency fractures following ipsilateral total knee arthroplasty

IntroductionOnly a few reports have described calcaneal insufficiency fractures (IFs) following total knee arthroplasty (TKA). Herein, we describe nine cases of calcaneal IFs following ipsilateral TKA. The purpose of this study was to investigate the incidence of calcaneal fractures following TKA and determine the characteristics of patients with IFs. Patients and methodsWe retrospectively investigated cases of calcaneal IF that occurred following TKA. We collected and analyzed radiographic and magnetic resonance imaging (MRI) findings as well as patient demographic data. We compared the demographic data, bone mineral density (BMD), and preoperative hip-knee-ankle angle (HKA) between cases with a calcaneal fracture following TKA and 100 cases without a fracture following TKA. ResultsWe performed a total of 1548 knee arthroplasties at our clinic from 2011 to 2020. Nine calcaneal IFs in eight patients were diagnosed following ipsilateral TKA. All patients were women with varus knee osteoarthritis (mean age, 71.8 years). The average change in the alignment angle was 14.7° ± 5.4°. In eight cases, dysfunction was observed in the opposite lower limb. The postoperative onset of hindfoot pain started at an average of 5.6 months. In seven patients, calcaneal fractures occurred idiopathically, but in one patient, two fractures occurred after long-distance walking. No abnormal findings on a calcaneus radiograph were seen for six fractures. MRI demonstrated a definite fracture line and bone marrow edema in all patients. All patients, except one with type 2 diabetes mellitus (T2DM), had osteoporosis. Fractures healed without complications in eight patients; however, the calcaneal anterior facet fracture became displaced and caused a flat foot in one case. The calcaneal IF rate was 0.58% among all cases. Besides one case with T2DM, significant differences were observed in preoperative HKA and BMD between cases with a calcaneal fracture following TKA and those without a fracture. ConclusionsA change in the load on the calcaneus due to changes in the alignment of the lower extremities after TKA may cause calcaneal IFs. Orthopedic surgeons should be aware of the possible occurrence of calcaneal IFs following TKA, especially in women with osteoporosis and severe varus knee.

Is Cooled Radiofrequency Genicular Nerve Block and Ablation a Viable Option for the Treatment of Knee Osteoarthritis?

BackgroundThe purpose of this study was to determine demographic and psychosocial factors that influence the effectiveness of cooled radiofrequency genicular nerve ablation (C-RFA) and block in patients with chronic knee pain secondary to osteoarthritis (OA).MethodsA retrospective review was completed including patients with knee OA who underwent genicular nerve ablation or block or both. Patient information collected included opioid use, psychological comorbidities, smoking history, body mass index, and medical comorbidities. Success was defined using the Osteoarthritis Research Society International criterion of greater than or equal to 50% reported pain relief from the procedure. Patients without a diagnosis of knee OA and patients with ipsilateral total knee arthroplasty were excluded. Patient factors were compared between (1) those that did or did not respond to the initial block and (2) those that did or did not respond to C-RFA.ResultsOf the 176 subjects that underwent genicular nerve block, 31.8% failed to respond to the procedure. Subjects that failed the initial block were significantly more likely to have psychological comorbidities, smoking history, and diabetes. Of the subjects that proceeded to genicular nerve ablation, 53.7% reported less than 50% pain relief, and 46.3% reported pain relief greater than or equal to 50% at the first follow-up visit. While the presence of psychological comorbidities, smoking, and diabetes were associated with first-stage block failures, these patient factors were not associated with second-stage ablation failures.ConclusionsC-RFA may be an effective adjunct therapy as part of a multimodal pain regimen; however, individual patient characteristics must be considered.

Prior unilateral total hip arthroplasty does not influence the outcome of ipsilateral total knee arthroplasty.

To assess the influence of a prior well-functioning unilateral primary total hip arthroplasty (THA) on the functional outcome of a subsequent ipsilateral primary total knee arthroplasty (TKA). A retrospective case-control study of 92 patients older than 60years underwent unilateral primary TKA after a prior ipsilateral THA (THA-TKA group) and 92 matched patients underwent only TKA (TKA group). Clinical assessments were performed using the Knee Society Scores (KSS) and Harris Hip Score (HSS), quality of life by the Reduced Western Ontario and MacMaster Universities (WOMAC) and Short-Form 12 (SF-12) questionnaires. Radiological evaluation was also performed. Median follow-up after TKA was 7.2 (range 5-9) years. There were no significant differences between groups in baseline data at the TKA time. The mean gains in KSS were similar in both groups. At the last follow-up, there were no significant differences in WOMAC-pain or SF12-physical scores, but the WOMAC-function (p = 0.003) and SF12-mental (p = 0.018) scores were significantly better in the isolated TKA group. At the last follow-up, there were no significant differences in the radiological knee alignment or component positions. For aseptic reasons, the TKA survival at 8years in the TKA group was 95.8 (95% CI 87.8-100%), and 96.6% (95% CI 91.8-100%) in the THA-TKA group (ns). A well-functioning unilateral THA does not influence on the functional outcome of a subsequent ipsilateral TKA. This finding can help clinicians when counseling patients with hip and knee osteoarthritis. III.

Cement Arthrodesis of the Knee with a Custom Long Recon Nail After Failed Total Knee Arthroplasty: Surgical Technique and Results

Background and Objective: Persistent periprosthetic joint infection (PJI) is a devastating complication after Total Knee Arthroplasty (TKA). We hypothesize that our novel treatment algorithm utilizing a customized knee spanning recon nail combined with an antibiotic eluting cement spacer improves ambulation status and prevents recurrent PJI in patients with failed TKA and severe bone loss. Methods: In a retrospective case series, 15 consecutive patients who underwent knee arthrodesis after failed ipsilateral TKA secondary to infection from 2004-2017 with at least 1 year of follow-up were enrolled. The average age of patients at the time surgery was 68 (range 50-81) years with an average follow-up of 3.2 (range 1-6) years. Post-surgical ambulation status and eradication of index infection were analyzed as primary outcomes using McNemar’s test for before-and-after study design with p&lt;0.05 for significance. Results: Cement arthrodesis significantly improved ambulation with 67% (10/15) of patients unable to ambulate before arthrodesis and 93% (14/15) of patients able to ambulate at final follow-up (p=0.004). The complication rate was 20% (3/15). There were no periprosthetic fractures. Amongst patients who presented with active PJI, 91% (10/11) had eradication of their index infection final follow-up (p=0.002). Overall prevention of recurrent index infection was 93% (14/15) (p=0.0001). Conclusion: Cement arthrodesis utilizing a custom knee spanning recon nail combined with an antibiotic eluting spacer improves ambulation status and prevents or treats recurrent infection in the majority of patients who have failed total knee arthroplasty.

Validité de la mesure peropératoire de l’antéversion de la pièce fémorale et facteurs d’erreur dans l’arthroplastie totale de hanche non cimentée par voie postéro-latérale

BackgroundIntraoperative estimation of stem anteversion in total hip arthroplasty (THA) using postero-lateral approach is made by the surgeon's visual assessment, using the tibia as a guide, with the assumption that tibial axis is vertical to the trans-epicondylar axis. However, the accuracy of the intraoperative estimation has rarely been verified with postoperative CT-scans, with controversies regarding these measurements particularly in case of knee osteoarthritis. Therefore, we performed a prospective study to: (1) determine the accuracy of the intraoperative measurement and (2) investigate factors affecting the discrepancy between the surgeon's estimation and the real stem anteversion. HypothesisIntraoperative estimation of stem anteversion correlated with the real stem anteversion on CT scan. Patients and methodsSixty-seven THAs using cementless straight stems (65 patients) without ipsilateral total knee arthroplasty were prospectively evaluated to compare the intraoperative measurement of stem anteversion with the real stem anteversion on computed tomography (CT) scans. There were 33 men and 34 women with a mean age of 59.7 years (range, 27–84 years) at the time of surgery. Age, tibia plateau angle, native femoral anteversion, femoro-tibial angle, body mass index, operative site, gender, coronal and sagittal tilt of the stem, stem type, ipsilateral knee osteoarthritis, and preoperative diagnosis were analyzed to evaluate the factors affecting the discrepancy between the intraoperative and CT measurements. ResultsThe intraoperative estimation (mean, 21.5°±8.5°; range, 5.0°–39.0°) was greater than the CT measurement (mean, 19.5°±8.7°; range, 4.5°–38.5°) by 2.0°. The mean absolute value of discrepancy was 4.5°. The correlation coefficient between intraoperative and CT measurements was 0.837. The femoro-tibial angle was associated with the discrepancy between the two measurements. In the presence of genu varum deformity, the intraoperative measurement underestimated the stem anteversion. DiscussionAlthough intraoperative estimation of stem anteversion was slightly greater than the real stem anteversion, there was an excellent correlation between the two. The femoro-tibial angle should be considered to optimize the stem anteversion during cementless THA using postero-lateral approach. Level of evidenceIII, prospective case control study.

Use of Shorter Intramedullary Guide for Ipsilateral Total Knee Arthroplasty following Prior Total Hip Arthroplasty.

Alignment after total knee arthroplasty (TKA) plays an important role with respect to patient satisfaction and implant survivorship. In patients undergoing ipsilateral TKA with prior total hip arthroplasty (THA), the femoral intramedullary (IM) guide cannot be fully inserted into the femoral canal because of the prior THA. The purpose of this study was to determine the effect of femoral component alignment using a shorter IM guide during TKA in patients with an ipsilateral THA. We identified 42 patients undergoing ipsilateral TKA with the use of a short IM guide in the setting of a prior THA. A matched cohort group was identified from our total joint registry that included 42 patients who underwent primary TKA. The surgical goal was to achieve 5 degrees of valgus on the femoral side and 0 degree on the tibial side with an overall postoperative tibial-femoral angle of 5 degrees of valgus. Patients were evaluated clinically using Knee Society pain scores (KSSs), function scores, and with radiography. Both the tibial-femoral limb alignment and the femoral component alignment were compared using Student's t-test. There were no significant differences between the two groups with respect to sex, age, body mass index (BMI), pre- and postoperative KSSs. There was a statistically significant difference between the two groups with respect to radiographic tibial-femoral limb alignment, 4.33 degrees of valgus in the short stem THA-TKA group versus 5.4 degrees of valgus in the TKA group (p < 0.04); however, this difference did not correlate to a difference in postoperative outcomes. An adequate tibial-femoral component alignment was achieved in patients undergoing ipsilateral TKA with prior THA using a shortened IM femoral guide.

Guide Pin Placement Technique for Total Ankle Replacement in Patients Who Had Ipsilateral Total Knee Arthroplasty.

Level V.

Subsequent Total Joint Arthroplasty After Primary Total Knee or Hip Arthroplasty

Despite the large increase in total hip arthroplasties and total knee arthroplasties, the incidence and prevalence of additional contralateral or ipsilateral joint arthroplasty are poorly understood. The purpose of this study was to determine the rate of additional joint arthroplasty after a primary total hip arthroplasty or total knee arthroplasty. This historical cohort study identified population-based cohorts of patients who underwent primary total hip arthroplasty (n = 1,933) or total knee arthroplasty (n = 2,139) between 1969 and 2008. Patients underwent passive follow-up through their medical records beginning with the primary total hip arthroplasty or total knee arthroplasty. We assessed the likelihood of undergoing a subsequent total joint arthroplasty, including simultaneous and staged bilateral procedures. Age, sex, and calendar year were evaluated as potential predictors of subsequent arthroplasty. During a mean follow-up of 12 years after an initial total hip arthroplasty, we observed 422 contralateral total hip arthroplasties (29% at 20 years), 76 contralateral total knee arthroplasties (6% at 10 years), and 32 ipsilateral total knee arthroplasties (2% at 20 years). Younger age was a significant predictor of contralateral total hip arthroplasty (p < 0.0001), but not a predictor of the subsequent risk of total knee arthroplasty. During a mean follow-up of 11 years after an initial total knee arthroplasty, we observed 809 contralateral total knee arthroplasties (45% at 20 years), 31 contralateral total hip arthroplasties (3% at 20 years), and 29 ipsilateral total hip arthroplasties (2% at 20 years). Older age was a significant predictor of ipsilateral or contralateral total hip arthroplasty (p < 0.001). Patients undergoing total hip arthroplasty or total knee arthroplasty can be informed of a 30% to 45% chance of a surgical procedure in a contralateral cognate joint and about a 5% chance of a surgical procedure in noncognate joints within 20 years of initial arthroplasty. Increased risk of contralateral total knee arthroplasty following an initial total hip arthroplasty may be due to gait changes prior to and/or following total hip arthroplasty. The higher prevalence of bilateral total hip arthroplasty in younger patients may result from bilateral disease processes that selectively affect the young hip, such as osteonecrosis, or structural hip problems, such as acetabular dysplasia or femoroacetabular impingement. Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.

The John N. Insall Award: Do Intraarticular Injections Increase the Risk of Infection After TKA?

Infection after total knee arthroplasty (TKA) can result in disastrous consequences. Previous research regarding injections and risk of TKA infection have produced conflicting results and in general have been limited by small cohort size. The purpose of this study was to evaluate if intraarticular injection before TKA increases the risk of postoperative infection and to identify if time between injection and TKA affect the risk of TKA infection. The Humana data set was reviewed from 2007 to 2014 for all patients who received a knee injection before TKA. Current Procedural Terminology (CPT) codes and laterality modifiers were used to identify patients who underwent knee injection followed by ipsilateral TKA. Postoperative infection within 6 months of TKA was identified using International Classification of Diseases, 9th Revision/CPT codes that represent two infectious endpoints: any postoperative surgical site infection (encompasses all severities of infection) and operative intervention for TKA infection (surrogate for deep TKA infection). The injection cohort was stratified into 12 subgroups by monthly intervals out to 12 months corresponding to the number of months that had elapsed between injection and TKA. Risk of postoperative infection was compared between the injection and no injection cohorts. In total, 29,603 TKAs (35%) had an injection in the ipsilateral knee before the TKA procedure and 54,081 TKA cases (65%) did not. The PearlDiver database does not currently support line-by-line output of patient data, and so we were unable to perform a multivariate analysis to determine whether other important factors may have varied between the study groups that might have had a differential influence on the risk of infection between those groups. However, the Charlson Comorbidity index was no different between the injection and no injection cohorts (2.9 for both) suggesting similar comorbidity profiles between the groups. The proportion of TKAs developing any postoperative infection was higher among TKAs that received an injection before TKA than in those that did not (4.4% versus 3.6%; odds ratio [OR], 1.23; 95% confidence interval [CI], 1.15-1.33; p < 0.001). Likewise, the proportion of TKAs developing infection resulting in return to the operating room after TKA was also higher among TKAs that received an injection before TKA than those that did not (1.49% versus 1.04%; OR, 1.4; 95% CI, 1.3-1.63; p < 0.001). Month-by-month analysis of time between injection and TKA revealed the odds of any postoperative infection remained higher for the injection cohort out to a duration of 6 months between injection and TKA (ORs ranged 1.23 to 1.46 when 1-6 months between injection and TKA; p < 0.05 for all) as did the odds of operative intervention for TKA infection when injection occurred within 7 months of TKA (OR ranged from 1.38 to 1.88 when 1-7 months between injection and TKA; p < 0.05 for all). When the duration between injection and TKA was longer than 6 or 7 months, the ORs were no longer elevated at these endpoints, respectively. Injection before TKA was associated with a higher risk of postoperative infection and appears to be time-dependent with closer proximity between injection and TKA having increased odds of infection. Further research is needed to better evaluate the risk injection before TKA poses for TKA infection; a more definitive relationship could be established with a multivariate analysis to control for other known risk factors for TKA infection. Level III, therapeutic study.

Custom intramedullary intercalating device for treatment of supracondylar fracture between constrained total knee arthroplasty and well-fixed total hip arthroplasty

Management of periprosthetic fractures between ipsilateral total knee arthroplasty (TKA) and total hip arthroplasty (THA) is difficult, and is further complicated in the setting of poor femoral bone stock. We present a case of supracondylar fracture between THA and long-stemmed TKA femoral components in a patient with rheumatoid arthritis, deficient metaphyseal bone stock, and recurrent fractures. A long custom intramedullary intercalating component was devised to link the well-fixed existing THA stem to a revision distal femoral component. The resulting construct was stable and allowed for full weight-bearing ambulation, representing a useful treatment option in the management of periprosthetic fractures between revision TKA and well-fixed THA.

Low Complication Rate of LISS for Femur Fractures Adjacent to Stable Hip or Knee Arthroplasty

Fractures of the femur after a knee or hip arthroplasty historically have been plagued with high complication rates. The Less Invasive Stabilization System (LISS) has theoretical advantages of improved biomechanics and limited insult to the bone's vascular supply. We theorized that the LISS would have a lower complication rate than historical controls for these fractures. Patients who were treated with a LISS at two Level I trauma centers from July 2001 to July 2003 were prospectively followed up. The inclusion criteria were an acute fracture of the femur treated with a LISS in a patient with a stable ipsilateral total knee prosthesis and/or hip pros- thesis. There were 24 patients in the study group. The injury mechanism was a low-energy fall for all patients. All patients were females with an average age of 79.5 years (range. 64-93 years). Ten patients had ipsilateral hip arthroplasties, nine patients had ipsilateral total knee arthroplasties, and five patients had knee and hip arthroplasties. Followup was at an average of 48 weeks (range, 17-101 weeks). Eighteen of the 19 fractures in the surviving patients with followup healed uneventfully for a complication rate of 5.2%. One fracture was complicated by hardware pullout and was revised to a longer LISS that healed uneventfully. We think our data show that our patients had a low complication rate compared with that of historical controls, and we suggest that the LISS may be an appropriate treatment alternative for femur fractures associated with stable hip or knee prostheses. Therapeutic, Level IV.