Rotating Hinge Prosthesis Research Articles

Total knee replacement in severe genu recurvatum. High prosthetic survival rate without deformity recurrence, using rotating hinge prosthesis

IntroductionGenu recurvatum can originate from neurological and non-neurological causes. Its presence associated with knee osteoarthritis represents 1 % of the causes of total knee replacement (TKR). The aim of this retrospective study was to show the functional outcomes, recurrence rate and prosthetic survival in patients with genu recurvatum treated with articulated rotating hinge prostheses. Methodsbetween January of 2008 and December of 2021, we performed 3224 primary TKR, of which 34 (1 %) had recurvatum. This was defined as hyperextension ≥10°. Inclusion crirteria were patients with primary TKR and recurvatum that were treated with a rotating hinge prosthesis (Endo Model, Walderman Link, Ham, Germany), and completed a minimum follow-up of 24 months. Final series consisted in 23 patients with 25 TKR with 15 (65.22 %) females and a mean age of 66.8 ± 14.2 years old. The median follow-up was 5.0 (range 2.11–11.5). Clinical analysis was performed with the use of Knee Society Score (KSS) and Western Ontario & McMaster Universities Osteoarthritis Index (WOMAC). Prosthetic survival rate was calculated with a Kaplan-Meier curve considering as the endpoint of the analysis revision due to any reason. Recurrence was defined as the presence of hyperextension ≥ 5° after surgery. Resultsof the 23 patients, 9 (39.13 %) had history of neurological disorders. Median recurvatum observed was 20.12° (range 13.0° - 30.2°). A median of 19.6° (range 10.1° - 55.4°) valgus misalignment was observed in 19 patients and 10.7° (range 2.0–23.5°) of varus was observed in 6 (24 %) patients. Clinical and functional KSS improved significantly after 12 months (from 34.2 ± 9.8 and 40.1 ± 12.6 to 82.1 ± 7.5 and 89.2 ± 6.8 respectively; p < 0.01) and at the end of the study (84.3 ± 7.5 and 90.0 ± 11.3; p < 0.01). Final mean WOMAC value was 24.1 ± 9.6. One (4.0 %) complication was registered after surgery (superficial infection). Four (16.0 %) patients had demarcation. Prosthetic survival rate was 100 % at the end of the study. ConclusionThe rotating hinge prosthesis restores joint function in patients with severe knee osteoarthritis with and without neurological disorders, without recurrence of misalignment and with excellent survival rates.

Rotating-Hinge Total Knee Arthroplasty: Clinical and Radiographic Results from a Medium-Term, Multi-Center Study in a Latin American Population

Background: Hinged prostheses are a good choice in the setting of complex knee arthroplasty. Nevertheless, the results could be different in the Latin-American people. Methods: A retrospective follow-up was performed. Seventy-six patients underwent pTKA using hinged prosthesis from 2012 to 2017. Survival analysis was performed with the Kaplan-Meier method. Functional results were assessed using Oxford Knee Score (OKS), OKS-APQ (Activity and Participation Questionnaire) and KOOS-12. Radiologic assessment was performed at each follow-up. In all the surgeries the rotating-hinge prosthesis solved the cases of complex knee surgery. Results: Seventy-six patients underwent pTKA using hinged prosthesis from 2012 to 2017. Survival analysis was performed with the Kaplan-Meier method. Functional results were assessed using Oxford Knee Score (OKS), OKS-APQ (Activity and Participation Questionnaire) and KOOS-12. Radiologic assessment was performed at each follow-up. In all the surgeries the rotating-hinge prosthesis solved the cases of complex knee surgery. Hinge prostheses for complex knee arthroplasty in Latin-American people have a 10-year survivorship of 90.8% which is within the range of 51% to 92.5%, shown in a recent literature review of non-Latin American world population. Conclusions: Rotating Hinge prostheses are a good option for patients with major deformities, grade 3 ligament instability, neurological sequalae that compromises the knee joint and severe bone loss. The Latin-American population shows a similar behavior in terms of survivorship in comparison with the literature from the rest of the world. However, comparative studies with greater statistical power are needed to show more accurate conclusions. Level of Evidence: Level III

High Rates of Early Septic Failure, but Low Rates of Aseptic Loosening After Revision Total Knee Arthroplasty With Contemporary Rotating-Hinge Prostheses

BackgroundThe purpose of this study was to determine implant survivorship and functional outcomes for revision total knee arthroplasty (rTKA) with contemporary rotating-hinge knee implants. MethodsA retrospective review identified 115 rTKAs using contemporary rotating-hinge implants from 2014 to 2018 for the treatment of instability (34, 30%), reimplantation after periprosthetic joint infection (PJI) (33, 29%), aseptic loosening (25, 22%), arthrofibrosis (14, 12%), periprosthetic fracture (4, 3%), osteolysis (4, 3%), and femoral component fracture (1, 1%). There were 70 women (61%), and the mean age was 67 years (range, 27 to 94). The mean follow-up was 3 years (range, 2 to 6). Kaplan-Meier analysis and Cox proportional hazard models estimated survivorship. ResultsThe re-revision rate was 20% (23 of 115) at an average of 18 months postoperatively. Re-revision indications included PJI (n = 14), aseptic loosening (n = 4), arthrofibrosis (n = 2), instability/malalignment (n = 1), femoral stem fracture (n = 1), and hinge mechanism disruption (n = 1). At 2 and 5 years, survivorship free from all-cause re-revision was 86 and 64%, and survivorship free from re-revision for aseptic loosening was 100 and 87%, respectively. Use of a rotating-hinge implant in reimplantation after PJI was a risk factor for subsequent re-revision (hazard ratio = 2.4, P = 0.046). On a radiographic review of unrevised rotating-hinges, there were major radiolucent lines around 2 femoral and 5 tibial components. The mean Knee Injury and Osteoarthritis Outcomes Score for Joint Replacement increased from 43 preoperatively to 60 at 1 year (P < 0.001). ConclusionsIn patients treated with a rotating-hinge implant for rTKA, there were relatively poor 2-year (86%) and 5-year (64%) survivorship free from all-cause re-revision, most commonly due to PJI. Midterm survivorship free from re-revision for aseptic loosening was modest (87%). There should be a goal to mitigate complications in complex rTKAs with rotating-hinge implants, namely PJI.

Failure of the Yoke With a Rotating-Hinge Total Knee Arthroplasty: A Case Report.

A patient underwent revision of a total knee replacement to a cementless rotating-hinge prosthesis. The femoral component became loose, but due to the patient's frailty and cognitive decline, revision was not performed. Subsequently, the yoke failed, dissociating the femoral and tibial components, necessitating a single-stage revision. This case underlines the need for robust fixation of components of rotating-hinge knee replacements to avoid mechanical failures. It contributes valuable insights to the limited literature on yoke failure in total knee arthroplasty, emphasizing the importance of implant design, patient selection, and surgical technique to prevent such complications.

GMK rotating hinge prosthesis. A valid option for complex revision knee prosthetic surgery

revision joint replacement surgery presents a surgical challenge. The use of rotating hinge prostheses is an option in patients with femorotibial bone defects, ligament insufficiency, or significant deformities. The aim of this study was to evaluate the clinical, functional, and radiological outcomes of a series of patients who underwent surgery using the GMK Hinge (Medacta®) rotational hinge model. a descriptive, retrospective, and analytical study was conducted on a series of 36 patients, with a mean age of 72.5 years (47-85), operated on by the same surgical team between January 2015 and January 2022. The etiology of revision was chronic infection in 38.9% of cases, instability in 33.3%, aseptic loosening in 19.4%, and stiffness in 8.4%. The Knee Society Score (KSS) and the Forgotten Joint Score (FJS) were used to assess functional outcomes. The degree of femorotibial bone defect was evaluated using the Anderson Orthopaedic Research Institute (AORI) classification. Postoperative complications are also recorded. a total of 36 patients, 17 males and 19 females, were included, with a mean follow-up of 30 months (12-66). Twelve patients had type 1 defects, ten had 2A defects, ten had 2B defects, and two had type 3 defects on the femoral side, with the use of wedges required for asymmetrical defects (21 patients). The predominant tibial defect was type 1 without the need for wedges. The majority achieved a satisfactory outcome on the KSS scale (72.2 ± 9.4), with significant differences compared to the previous KSS (54.3 ± 8.9). A score of 31 (12-67) was also obtained on the FJS scale. Postoperative complications were present in 16.7% of patients. complex prosthetic revision surgery using a rotating hinge prosthesis represents a suitable therapeutic option, yielding appropriate clinical and functional outcomes, albeit not without complications.

Is a greater degree of constraint really harmful? Clinical biomechanical comparative study between condylar constrained knee and rotating hinge prosthesis

BackgroundThe real degree of constraint of rotating hinge knee and condylar constrained prostheses is a matter of discussion in revision knee arthroplasty. The objective of this study is to compare the tibial rotation between implants in the clinical settings. MethodsAn investigator blinded experimental study was designed including 20 patients: in 10 of them a rotating hinge knee prosthesis (Endomodel®, LINK) was implanted and in the remaining 10 a constrained condylar knee prosthesis (LCCK®, Zimmer) was used. A medial parapatellar approach was performed and implantation was performed according to conventional surgical technique. Tibial rotation was measured with two accelerometers in full extension and at 30°, 60° and 90° of flexion. Pre and postoperative Knee Injury and Osteoarthritis Outcome Score was recorded. FindingsBoth groups were homogenous in age (73.4 years in rotating hinge knee prosthesis vs 74 years in constrained condylar knee group), sex, laterality and preoperative Knee Injury and Osteoarthritis Outcome Score (p > 0.05). The postoperative Knee Injury and Osteoarthritis Outcome Score was significantly higher in the rotating hinge knee prosthesis group (80.98 vs 76.28).The degrees of tibial rotation measured by inertial sensors in the rotating hinge knee prosthesis group were also significantly higher than those measured in the constrained condylar knee group (5.66° vs 2.1°) with p = 0.001. InterpretationRotating hinge knee prosthesis appears to represent a lower rotational constraint degree than constrained condylar knee systems in clinical practice and it may increase the clinical satisfaction.The clinical significance: Rotating hinge knee prosthesis appears to represent a lower constraint degree than constrained condylar knee systems in clinical practice.

Satisfactory medium- to long-term outcomes of cemented rotating hinge prosthesis in revision total knee arthroplasty.

The aim of this study was to evaluate medium- to long-term outcomes and complications of the Stanmore Modular Individualised Lower Extremity System (SMILES) rotating hinge implant in revision total knee arthroplasty (rTKA) at a tertiary unit. It is hypothesized that this fully cemented construct leads to satisfactory clinical outcomes. A retrospective consecutive study of all patients who underwent a rTKA using the fully cemented SMILES rotating hinge prosthesis between 2005 to 2018. Outcome measures included aseptic loosening, reoperations, revision for any cause, complications, and survivorship. Patients and implant survivorship data were identified through both prospectively collected local hospital electronic databases and linked data from the National Joint Registry/NHS Personal Demographic Service. Kaplan-Meier survival analysis was used at ten years. Overall, 69 consecutive patients (69 knees) were included with a median age of 78 years (interquartile range 69 to 84), and there were 46 females (66.7%). Indications were septic revisions in 26 (37.7%), and aseptic aetiology in the remining 43 (62.3%). The mean follow-up was 9.7 years (4 to 18), and the overall complication was rate was 7.24%, all with patellofemoral complications. Failure rate with 'any cause revision' was 5.8%. There was one case of aseptic loosening of the femoral component. At ten years, 17/69 patients (24.63%) had died, and implant survivorship was 92.2%. In our experience, the SMILES rotating hinge prosthesis achieves satisfactory long-term outcomes with ten-year implant survivorship of 92.2% and a patellofemoral complication rate of 7.24%.

Metaphyseal cones combined with diaphyseal impaction grafting provide good outcomes and survival in a complex revision total knee arthroplasty: a matched comparative analysis.

To compare clinical and radiological outcomes, implant survivorship at a minimum of 1-year follow-up using metaphyseal trabecular cones with or without impaction grafting in a complex revision TKA. A retrospective comparative matched analysis was performed and 15 patients who underwent revision surgery using the combination of porous trabecular metaphyseal cone and diaphyseal impaction grafting (MC-IBG) were matched with a group of 13 patients who also underwent revision surgery using metaphyseal cone (MC) without impaction grafting. All included patients presented severe bone defect (AORI 2,3) and a rotating-hinge prosthesis were implanted. Both groups were comparable regarding the baseline demographic and clinical data. Patients had previously undergone a mean of 4 (range, 2-12) and 3 (range, 2-5) previous proceduresin the MC-IBG and MC groups, respectively. The indications for revision were aseptic loosening in 11 (73.3%) and 11 (84.6%) patients; prosthetic joint infection in 4 (26.7%) and 2 (15.4%) in the MC-IBG and MC groups, respectively. There was no significant difference in the mean postoperative Knee Society Score between the study groups (p = 0.806). Overall, 4 patients had further revision. Two patients were revised in the MC-IBG group, one patient for aseptic loosening and the second one after 2 episodes of instability. Two patients in the MC group presented prosthetic joint infection and underwent a two-stage reimplantation. No significant difference was observed between the study groups at comparison (p = 0.92). Trabecular metal cones with diaphyseal impaction grafting provide an alternative technique in acomplex revision TKAsurgery with early clinical and radiographic success.

Treatment of neuropathic unstable knee osteoarthritis by a condylar, rotating-hinge prosthesis with cementless pentagonal stem: a case series

Total knee arthroplasty (TKA) in the neuropathic unstable knee (NUK) setting is classically a challenging orthopedic problem due to intraoperative technical difficulties and a higher frequency of periprosthetic complications. More recently, satisfactory results have been reported using improved constraints, stems and revision-type TKA components. The study aims to present long-term results of a small case series with NUK osteoarthritis reconstructed by a condylar, semi-constrained prosthesis with a polygonal, hydroxyapatite-coated (HA-coated) press-fit stem. From 2009 through 2010, three knees in three patients with advanced NUK arthropathy underwent TKAs in our institution using the PENTA® prosthesis. The average age at surgery was 44 years (32–58). The patients were followed up for a mean period of 124 months (120–128). The etiology of NUK was determined to be poliomyelitis sequela in 2 cases and spinal cord injury in one case. Functional outcomes were assessed with Knee Society (KS) Knee and Function Scores, and radiological outcomes were evaluated with ISOLS radiographic implant scores. Patients were monitored for complications clinically and radiologically. KS knee scores improved from a mean of 12,3 (0–37) preoperatively to 71,3 (65–77) and KS function scores improved from a mean of 1,7 (0–5) preoperatively to 68,3 (55–80) at the latest follow-up. Radiological outcomes were excellent according to ISOLS scores, and no complications were observed. Although this is a small case series, the significant improvement in functional scores, excellent radiological outcome, and implant survival at the end of a long follow-up period warrants TKA with a semi-constrained hinged implant in the setting of NUK. PENTA® prosthesis offers a good choice of implant with its hydroxyapatite-coated, press-fit, pentagonal stem and precisely designed rotating hinge.

What's New in Musculoskeletal Tumor Surgery.

What's New in Musculoskeletal Tumor Surgery.

Revision Total Knee Arthroplasty With a Rotating-Hinge Prosthesis Mated to a Well-Fixed Femoral Sleeve.

Some knee systems have the unique capability to mate a new hinged femoral component to a well-fixed metaphyseal sleeve from a prior revision. We compared survivorship, radiographs, and clinical outcomes of a rotating-hinge total knee arthroplasty mated to a new metaphyseal sleeve vs a well-fixed sleeve. Sixty patients with an S-ROM Noiles (DePuy Synthes, Warsaw, IN) rotating-hinge total knee arthroplasty implanted from 1998 to 2019 were retrospectively reviewed. Nine patients (15%) had the femoral component mated to a well-fixed sleeve and 51 patients (85%) had a new sleeve. Mean age was 68 years, 68% were female, and mean body mass index was 33 kg/m2. The incidences of re-revision and reoperation were calculated, Knee Society Scores were measured, and radiographs were reviewed. Mean follow-up was 5 years. There were 2 re-revisions (22%) in patients with a well-fixed sleeve: 1 for infection and 1 for aseptic loosening of the femur and tibia. There were no unique failures including the taper junction. Nine patients (18%) with a new sleeve were re-revised: 7 for infection and 2 for tibial aseptic loosening. The mean Knee Society Score for all patients improved from 39 to 73. Radiographically, all components were well fixed except for one loose femur in a patient with a new sleeve. Mating an S-ROM femur to a well-fixed sleeve from a prior revision is a safe, simple, and durable option in the short term that prevents morbidity associated with removal of a well-fixed sleeve. No new modes of failure were observed. IV (retrospective), Therapeutic.

Similar outcomes of constrained condylar knee and rotating hinge prosthesis in revision surgery for extension instability after primary total knee arthroplasty

BackgroundInstability is one of the most common reasons for total knee arthroplasty (TKA) failure. Constrained prosthesis can be used for significant ligamentous laxity, but there is not much evidence on the appropriate level of restriction for unstable varus-valgus TKA. The objective of this study was to compare the outcome and survival at a minimum follow-up of five years between rotating hinge knee prosthesis (RHK) and constrained condylar knee prosthesis (CCK) for extension instability following primary TKA. HypothesisFor symptomatic extension instability after primary TKA, good functional outcomes and survival can be achieved with both designs. Material and methodsConsecutive patients with unstable primary TKA who underwent revision with either RHK (n=34) or CCK (n=30) were retrospectively compared. Assessments were performed by the Knee Society Scores (KSS), and visual analogue scales (VAS) for pain and patient satisfaction. Radiological evaluation was made. Complications and re-operations were analyzed. ResultsMean post-operative follow-up was 10.3 (range 5-16) years for both groups. At the final follow-up, there was no significant difference between groups in the KSS-knee (p=0.228) or KSS-function (p=0.324) score, VAS-pain (p=0.563), VAS-satisfaction (p=0.780), major complication rate (p=0.194), or TKA survival at 10 years (p=0.091). ConclusionThe present study showed comparable good functional outcomes and survival at long-term between RHK and CCK arthroplasties. Both designs can be recommended for revision of total knee arthroplasty with symptomatic extension instability. Level of evidenceLevel III.

Rotating Hinge Revision Total Knee Arthroplasty for Severe Arthrofibrosis.

First, remove all soft-tissue and osseous sources of stiffness and adequately expose the knee, then remove all previous components. Create a stable and balanced extension gap, and, conversely, a relatively loose flexion gap, which allows for a substantial increase in range of motion. Then, in order to prevent instability in flexion, a rotating hinge prosthesis is utilized, which allows for appropriate kinematic motion despite gap imbalance. Additional steps to regain flexion include medial and lateral distal femoral partial condylectomies, as well as patellar component revision. The first line of treatment for stiffness following total knee arthroplasty is nonoperative and is mainly focused on physical therapy3. Manipulation under anesthesia can also be performed within the first 12 weeks postoperatively3. Surgical treatments can include arthroscopic debridement as well as open debridement with possible polyethylene liner exchange. If there is a mechanical cause for stiffness, then this should also be addressed surgically. For cases of arthrofibrosis without a clear mechanical etiology or for cases in which the above treatment has failed, complete revision of the femoral and tibial components should be considered3. An alternative option to the technique proposed here is to utilize a varus-valgus constrained implant. Revision with a hinged implant allows for a more aggressive approach to regaining motion, as compared with all other surgical alternatives. By revising all components, the surgeon is able to remove all sources of stiffness and reconstruct the knee until as much range of motion as possible is achieved. Unfortunately, even with balanced extension and flexion gaps, refractory stiffness is common. A solution for this residual stiffness is to unbalance the gaps and create a loose flexion gap. By doing so, the surgeon is advised to switch to a hinged implant to create a kinematically balanced knee. Any other revision implant, such as a varus-valgus constrained implant, would risk flexion instability. Several studies have examined the use of revision total knee arthroplasty with a hinged implant for arthrofibrosis and have showed substantial improvements in knee range of motion. Bingham et al. showed that the rotating hinge group had a 20° improvement in range of motion (p = 0.048)1. Hermans et al. found a 35.8° flexion gain in the hinge group compared with a 14.2° flexion gain in the varus-valgus constrained group (p = 0.0002)4. van Rensch et al. found a median gain of 45° of range of motion5. Patients should be aware that this procedure involving the use of a hinged implant has similar risks to other revision total knee arthroplasty procedures; specifically, there is a risk of recurrent arthrofibrosis as well as mechanical complications1,5. Achieve adequate exposure with a quadriceps snip.Perform a thorough synovectomy and debridement.Create a balanced extension gap with a relatively loose flexion gap.Distalize the joint line by resecting additional proximal tibia in cases of patella baja.Beware of refractory stiffness as a result of a scarred extensor mechanism.Consider revising the patellar component.Consider performing a partial condylectomy at the medial and lateral distal aspects of the femur. TKA = total knee arthroplastyAP = anteroposteriorCT = computed tomographyMRI = magnetic resonance imagingRHK = rotating hinge kneeNSAIDs = nonsteroidal anti-inflammatory drugs.

Patient-reported outcomes after primary rotating hinge total knee arthroplasty: a multi-centre clinical cohort study.

Rotating hinge prostheses for total knee arthroplasty (TKA) are mostly used in revision setting; however, evidence on the use of these constrained devices in primary setting is scarce and inconsistent. Therefore, we aimed to evaluate the functional outcomes after third-generation rotating hinge implants in primary TKA with a minimal follow-up of twoyears in a large dual-centre observational retrospective clinical trial. The hospital databases of two centres were searched for primary rotating hinge arthroplasty from January 2007 to January 2015. A minimum follow-up of at least twoyears was assured. Patients meeting the inclusion criteria were asked to fill out two self-reported functional scores, the Oxford Knee Score (OKS) and Forgotten Joint Score (FJS), to measure the functional status of the knee. In total, 267 primary rotating hinge knee arthroplasties in 242 patients were performed in two centres. The three major indications were axial malalignment (valgus/varus > 15°), 87/267 (33%), persistent ligamentous instability (28%) and neuromuscular disorders (12%). 184 patients with 202 primary rotating hinge knee arthroplasties could be included that provided data of the self-reported outcome measures (OKS and FJS). A mean OKS score of 37.71 (± 9.23) and a mean FJS score of 63.65 (± 31.01) could be obtained. This large clinical study suggests that constrained devices provide the best results when treating bone-on-bone tricompartimental osteoarthritis of the knee with severe axial deviation (valgus/varus > 15°) and/or persistent ligamentous instability.

Handheld computer-navigated constrained total knee arthroplasty for complex extra-articular deformities.

The present study aimed to assess the postoperative alignment and clinical outcomes of patients with complex extra-articular deformities (EADs) undergoing computer-assisted surgery (CAS) for constrained total knee arthroplasty (TKA) with modular stem extensions. From May 2015 to July 2018, ten patients with EADs scheduled for constrained TKA were enrolled retrospectively. The preoperative average deviation from neutral (= 180°) mechanical axis was 15.3° (range of coronal alignment: 150.9° varus-202.9° valgus). Alignment was assessed using an accelerometer-based handheld CAS system. On long-leg films, the positions of the components and possible stems were analysed and templated preoperatively. The average follow-up was 3.3years (range: 2.0-4.6years). The postoperative mechanical axis was within ± 3.0° from neutral in nine patients. In all patients, the Knee Society score (KSS) and range of motion improved significantly. A constrained condylar and a rotating hinge prosthesis were used in five patients each. In eight patients, the 100-mm cementless stem that was preferred by the authors was found to be unusable for the femur or the tibia in the planning stage. For the femur, a cementless 100-mm stem was used in three, and a cemented 30-mm stem in five patients; a femoral stem was not usable in two patients. For the tibia, a cementless 100-mm stem was used in six, and a cemented 30-mm stem in two patients; a monoblock rotating hinge tibia was used in two patients. Complex EADs were excellently managed during constrained TKA implantation using the handheld CAS system. Templating allowed the possible stem lengths to be identified and prevented anatomical conflict with the CAS-configured mechanical alignment. Limb alignment and function improved significantly after surgery. No intra- or postoperative complications occurred. Level IV, retrospective study.

Mid-term results and survival rates following a single-design rotating hinge knee arthroplasty in non-tumor conditions in a Pakistani population

BackgroundInformation regarding the use of hinged implants in non-oncological conditions is limited in our region due to a lack of adequate data collection and follow-up. The purpose of this study is to evaluate mid-term results and risk factors affecting the survivorship of third-generation rotating hinge knee (RHK) patients in non-oncological conditions.MethodsWe retrospectively reviewed 41 single, third-generation, rotating hinge prostheses in three complex primary knee procedures and 38 revision knee surgeries in between 2007 to 2014. Implant survival was assessed using the Kaplan-Meier method. Factors influencing implant survival were identified using the log-rank test. During the study period, clinical results along with complications were assessed. Clinical outcomes were assessed by using the Knee Society Score (KSS).ResultsRHK arthroplasty was used in 41 patients. Out of 41 patients, a RHK was used in three patients with a complex primary deformed knee whereas in 38 patients, a RHK was used in revision arthroplasty surgery. The cumulative implant survival rate with re-revision due to any cause was found to be 87.8% (95% CI 69.2–90.1) at 5–7 years. Prosthetic joint infection, peri-prosthetic fracture and extensor mechanism complications were the commonest mode of failure. The P value was found to be significant when comparing KSS pre-operatively and post-operatively.ConclusionThe cumulative implant survival rate was found to be 87.8%. Prosthetic joint infection was the commonest mode of failure in patients who underwent third-generation RHK surgery for variable indications. Being a patient with a high Charlson comorbidity index is the main risk factor associated with failure of the rotating hinge implant.

Rotating-hinge prosthesis for aseptic revision knee arthroplasty: A multicentre retrospective study of 127 cases with a mean follow-up of five years

BackgroundThe use of third-generation rotating-hinge knee prostheses has increased considerably in recent years. The more anatomical design of these prostheses, together with their controlled rotation system that reduces constraints generated by the single degree of liberty, have produced better outcomes. The objective of this study was to evaluate the clinical and radiological outcomes of revision knee arthroplasty for aseptic failure using rotating-hinge prostheses. HypothesisThe rotating-hinge knee prostheses currently used in France provide significant improvements in function and self-sufficiency of patients undergoing revision knee arthroplasty, with outcomes comparable to those reported with constrained condylar knees. Material and methodsA multicentre retrospective study was conducted in 17 centres, under the auspices of the SoFCOT. The cohort consisted of 127 patients (127 knees) operated on before 2013. The main reasons for knee revision were aseptic loosening, major instability, mechanical failure, and extensor apparatus failure. Function and self-sufficiency were assessed using the International Knee Society (IKS) score and the Devane score, respectively. Survival was defined with all-cause surgical revision as the end point. ResultsMean follow-up was 67.3±11.8 months (range, 13–180 months). Significant improvements (p<0.001) were seen in the total IKS score (+42 points), the IKS function score (+12 points), and the knee IKS score (+30 points). Paradoxically, the Devane score decreased by 0.44 point. The 5-year survival rate was 77% (95% confidence interval, 0.70–0.85). Postoperative complications developed in 29% of patients (infection, n=12; aseptic loosening, n=11; and fracture, n=7). DiscussionRotating-hinge prostheses provide satisfactory outcomes of knee arthroplasty revision and remain an effective option for complex cases, confirming our working hypothesis. Self-sufficiency diminishes slightly. The long-term outcomes obtained using rotating-hinge prostheses are, however, less satisfactory than those observed with constrained condylar knees for aseptic TKA revision, and the complication rate is higher, although the population and local circumstances are different. Discernment is therefore in order when determining the indications of rotating-hinge prostheses. Level of evidenceIV; retrospective cohort study.

A computer-assisted navigation technique for complex primary knee arthroplasty with intra-articular bone defect and instability: A case report and literature review

Correction of a combined severe varus, bone defect, and ligamentous instability in a complex primary knee replacement is a technically demanding procedure. In such instances, constrained or rotating-hinge prosthesis is usually considered. Computer-assisted surgery in extra-articular deformity correction is a widely accepted and advantageous approach, but difficult to apply for intra-articular deformity due to difficulties with defining anatomical references. Our case report describes a patient with severe osteoarthritis, with intra-articular bone defects and ligament instability. We performed a computer-assisted navigation technique by combining gap balancing and measured resection techniques, with a metaphyseal sleeve as a new joint-line reference. We used an unconstrained posterior-stabilized (PS) prosthesis, incorporating Knee Society Scores (KSS): KSS-knee and KSS-function improved from 0–91 and 5–85, respectively, at one-month postoperatively. Our technique exhibited good short-term clinical outcomes and may decrease the requirement for constrained or rotating-hinge prostheses in a complex primary case.

Condylar constrained knee prosthesis and rotating hinge prosthesis for revision total knee arthroplasty for mechanical failure have not the same indications and same results.

Purpose: This study aimed to evaluate whether there are any differences in outcomes and complication rates between condylar constrained knee (CCK) and rotating hinge knee (RHK) prostheses used for the first revision of total knee arthroplasty (rTKA) after mechanical failure. Methods: Sixty-three consecutive non-septic revisions of posterior stabilized implants using 33 CCK and 30 RHK prostheses were included. Clinical evaluation and revision rate were compared between the two groups at two years minimum follow-up. Results: The CCK group had significantly better clinical outcomes and satisfaction rates compared to patients with RHK (KSS-knee 70.5 versus 60.7 (p < 0.003) and KSS-function 74.9 versus 47.7 (p < 0.004) at 3.7 (2.0–9.4) years mean follow-up. Moreover, the clinical improvement was significantly higher for the CCK group concerning the KSS-Knee (+23.9 vs. +15.2 points, p = 0.03). The postoperative flexion was significantly better in the CCK group compared to the RHK group (115° vs. 103°, p = 0.01). The prosthesis-related complications and the re-revision rate were higher in the RHK group, especially due to patellofemoral complications and mechanical failures. Conclusions: CCK prostheses provided better clinical and functional outcomes and fewer complications than RHK prostheses when used for the first non-septic rTKA. CCK is a safe and effective implant for selected patients, while RHK should be used with caution as a salvage device for complex knee conditions, with particular attention to the balance of the extensor mechanism.

Risk Factors for Aseptic Loosening After Total Knee Arthroplasty with a Rotating-Hinge Implant

Background: Successful results have been reported in association with the use of a rotating-hinge prosthesis for primary total knee arthroplasty (TKA). The objective of the present study was to identify risk factors for aseptic loosening in patients who underwent primary TKA with rotating-hinge knee prostheses. Methods: The records of 1,235 patients who underwent primary TKA with a rotating-hinge prosthesis at our center were evaluated. A total of 125 patients who underwent revision were further evaluated according to the inclusion and exclusion criteria, and 33 patients who underwent revision because of aseptic loosening were then compared with a group of 30 patients who did not require revision surgery. All data, including radiographic measurements, were obtained from records prior to the primary TKA. Results: On the basis of our review of demographic, anthropometric, clinical, surgical, and radiographic findings, we found that higher body mass index (BMI) was associated with revision. The majority of patients with aseptic loosening had loosening of the femoral component. Furthermore, the inner femoral diameter at 20 cm proximal to the knee joint (on both anteroposterior and lateral images) was found to be predictive of revision among those with aseptic loosening. Receiver operating characteristic curve analysis showed that an inner diameter of the femur of &gt;19 mm on anteroposterior images had a sensitivity of 91% and specificity of 87% for predicting the need for revision surgery in patients with aseptic loosening. Conclusions: This is one of few studies that has focused on determining risk factors for the failure of rotating-hinge prostheses following TKA surgery. Our findings indicate that a novel variable, the inner (diaphyseal) diameter of the femur at the point 20 cm proximal to the knee joint, is an extremely reliable predictor of revision surgery in patients with aseptic loosening. Level of Evidence: Prognostic Level III. See Instructions for Authors for a complete description of levels of evidence.