The Accuracy of Patient-Specific Instrumentation with Laser Guidance in a Dynamic Total Hip Arthroplasty: A Radiological Evaluation.

The functional positioning of components in a total hip arthroplasty (THA) and its relationship with individual lumbopelvic kinematics and a patient's anatomy are being extensively studied. Patient-specific kinematic planning could be a game-changer; however, it should be accurately delivered intraoperatively. The main purpose of this study was to verify the reliability and accuracy of a patient-specific instrumentation (PSI) and laser-guided technique to replicate preoperative dynamic planning. Thirty-six patients were prospectively enrolled and received dynamic hip preoperative planning based on three functional lateral spinopelvic X-rays and a low dose CT scan. Three-dimensional (3D) printed PSI guides and laser-guided instrumentation were used intraoperatively. The orientation of the components, osteotomy level and change in hip length and offset were measured on postoperative CT scans and compared with the planned preoperative values. The length of surgery was compared with that of a matched group of thirty-six patients who underwent a conventional THA. The mean absolute deviation from the planned inclination and anteversion was 3.9° and 4.4°, respectively. In 92% of cases, both the inclination and anteversion were within +/- 10° of the planned values. Regarding the osteotomy level, offset change and limb length change, the mean deviation was, respectively, 1.6 mm, 2.6 mm and 2 mm. No statistically significant difference was detected when comparing the planned values with the achieved values. The mean surgical time was 71.4 min in the PSI group and 60.4 min in the conventional THA group (p < 0.05). Patient-specific and laser-guided instrumentation is safe and accurately reproduces dynamic planning in terms of the orientation of the components, osteotomy level, leg length and offset. Moreover, the increase in surgical time is negligible.

Metallic versus Non-Metallic Cerclage Cables System in Periprosthetic Hip Fracture Treatment: Single-Institution Experience at a Minimum 1-Year Follow-Up.

Metallic cerclage cables are reliable and cost-effective internal fixation devices, which are largely used in surgical practice for the treatment of periprosthetic fractures. Nevertheless, complications connected with their use have been described in the literature, including the following: third-body generation, failure and consequent migration, fraying, allergies, and injury to the surgical team. The development of new materials offers alternatives to traditional metallic cables. This study compares the outcomes between two groups of patients affected by periprosthetic hip fractures, treated with titanium cables or with ultra-high-molecular-weight polyethylene (UHMWPe) iso-elastic cables. Our retrospective study aims to compare the clinical and radiological outcomes of titanium cables and UHMWPe iso-elastic cables, isolated or associated with dedicated plates, for the surgical treatment of periprosthetic fractures with stable implants. Two groups of 30 (group A-metallic cables) and 24 (group B-UHMWPe iso-elastic cables) patients have been surgically treated in our institution for hip periprosthetic fractures, between September 2017 and June 2020. The mean age of the patients was 81 years in group A and 80 years in group B. In our study, we included fractures classified as B1 or C, according to the Vancouver postoperative fractures classification; the patients were evaluated retrospectively at 1 year postoperatively, regarding the following: surgery time, blood loss, partial weight-bearing time, radiographical healing time, Harris hip score, and postoperative complications. Comparable outcomes were observed in patients from both groups. Group A showed a higher complication rate compared to group B, at 1 year postoperatively. Non-metallic nylon fiber and ultra-high-molecular-weight polyethylene (UHMWPe) cerclage cables could represent a reliable fixation device, ensuring comparable healing and complication rates with traditional titanium cerclage cables.

Do serum markers correlate with invasiveness of the procedure in THA? A prospective randomized study comparing direct anterior and lateral approaches.

BACKGROUND: Advantages of minimally invasive approaches for total hip arthroplasty are still matter of debate. Serum markers have been assessed as objective method to quantify muscle damage after surgery but in literature ambiguous results have been reported. The aim of this prospective randomized study was to: 1) compare serum markers elevation between a minimally invasive direct anterior approach (DAA) and a direct lateral approach (DLA); 2) to establish a correlation between serum markers increase and other perioperative variables. HYPOTHESIS: A lesser elevation of markers could be found in patients who underwent a minimally invasive DAA. PATIENTS AND METHODS: Seventy patients were enrolled and randomly divided in two groups according to the type of the approach. All patients were treated with the same implant by the same surgeon and received the same rehabilitation protocol. Demographic data, preoperative Harris Hip Score (HHS) and operative time were recorded. Myoglobin, creatine kinase MB (CK-MB), troponin I, C-reactive protein (CRP), haemoglobin (HB) and pain levels were measured pre- and postoperatively. RESULTS: Mean postoperative rise were 524.9±134.6 and 667.8±409.5 for myoglobin, 4.8±2.5 and 6.6±3.7 for CK-MB, and 16.9±5.3 and 15.4±6.4 for PCR, in DAA and DLA groups, respectively. In both groups, postoperatively values were significantly higher than preoperatively (p<0.05). Comparing the two groups, no significant differences in serum markers elevations were found. A significantly lower postoperative pain was found in DAA group than in DLA group (2.9 vs. 4.2 and 2.7 vs. 3.6 in second and third day, respectively (p<0.05)). No significant correlation was present between the serum marker elevations and age, BMI, HHS, operative time, HB or pain levels (p>0.05). CONCLUSION: Serum markers of muscle damage and inflammation increased in the postoperative period without significant differences between DAA and DLA, even though overall trend was higher in DLA group. The DAA group had significantly lower levels of postoperative pain. No significant correlation between pain and serum markers levels was found. LEVEL OF EVIDENCE: I; randomized study.

Clinical and radiological outcomes of postoperative septic arthritis after anterior cruciate ligament reconstruction.

BACKGROUND: Septic arthritis after arthroscopic anterior cruciate ligament (ACL) reconstruction is a rare complication. In the literature, several treatments have been proposed. The aim of the study was to report our results using ambulatory irrigation of the knee and parenteral and oral antibiotics. METHODS: From January 2001 to December 2008, a total of 12 patients were treated for postoperative septic arthritis of the knee after ACL reconstruction in our hospital. The average age at trauma was 24 years (range 16-43 years). The treatment protocol included irrigation of the knee (for 2 days) and parenteral antibiotics and oral antibiotics subsequently. Repetitive irrigation was performed if necessary. The average duration of follow-up for our series was 38 months (range 6-54 months). Follow-up included International Knee Documentation Committee (IKDC) forms, radiography, Tegner and Lysholm scores, and KT-1000 arthrometric evaluation. RESULTS: In all cases treatment of infection was successful. Neither graft nor hardware removal was needed in any of the cases. At final examination, the pivot shift was negative in 10 of 12 patients, and it was 1+ in the other 2 patients; the Lachman was negative in all cases. The mean postoperative Tegner score was 7.2, and the mean Lysholm score was 98.3. In all, 10 of the 12 patients were graded as group A and the other 2 as group B using the IKDC form. The mean postoperative manual maximum KT-1000 side-to-side difference was 2.3. No significant bone tunnel enlargement was found at radiographic evaluation. CONCLUSIONS: The described treatment regimen gives reliable results for this complication. There were no recurrences of septic arthritis or bone infection. No further surgeries were required, and the graft was retained during the treatment of septic arthritis.

Hip arthroplasty for failed treatment of proximal femoral fractures.

Failed treatment of an intertrochanteric fracture typically leads to profound functional disability and pain. Salvage treatment with hip arthroplasty may be considered. The aim of this study was to evaluate the results and complications of hip arthroplasty performed as a salvage procedure after the failed treatment of an intertrochanteric hip fracture. Twenty-one patients were treated in our hospital with hip arthroplasty for failed treatment of intertrochanteric hip fracture. There were sixteen women and five men with a mean age of 75.8 years (range 61-85 years). Fourteen patients had failure of a previous nail fixation procedure, five had failure of a plate fixation, one of hip screws fixation and one of Ender nail fixation. In 19 out of 21 patients we performed a total hip arthroplasty-14 cases used modular implants with long-stems and five cases used a standard straight stem. In 2 of 21 cases we used a bipolar hemiarthroplasty. A statistically significant improvement was found comparing pre and postoperative conditions (p < 0.05). Our experience confirms that total hip arthroplasty is a satisfactory salvage procedure after failed treatment of an intertrochanteric fracture in elderly patients with few serious orthopaedic complications and acceptable clinical outcomes.

Is dual cup mobility better than hemiarthroplasty in patients with dementia and femoral neck fracture? A randomized controlled trial.

PURPOSE: Treatment of patients with dementia and hip fracture is challenging. Total hip arthroplasty (THA) with dual mobility cup (DMC) has been designed to reduce the rate of dislocation by increasing the stability of the implant. This study aimed to compare the dislocation rates of DMC THA with hemiarthroplasty (HA) in elderly patients with displaced femoral neck fracture (FNF) and a diagnosis of dementia. METHODS: All patients with a displaced FNF and dementia diagnosis were prospectively randomized to hemiarthroplasty or THA with DMC treatment during a 2-year period. Finally, the outcomes of 30 patients in the HA group were compared with those of 30 patients in the DMC THA group. Dislocation rate at a minimum follow-up of 1 year was evaluated as the primary outcome. Reoperation rate, time to surgery, surgical time, length of hospital stay, and 30-day and 1-year mortality were also evaluated. RESULTS: There was a significant difference regarding rates of dislocation in favor of THA with DMC and with regard to length of surgery (p = 0.04) in favor of bipolar HA. Dislocation occurred in five patients (16.6%) treated with bipolar HA and no one (0%) in patients treated with THA with DMC (p = 0.019). There was no difference with regard to the 30-day mortality, 1-year mortality, reoperations, and length of hospital stay between the two groups of patients. DISCUSSION: THA with DMC seems to be a safe and reliable choice to reduce the rate of dislocation at 1 year in patients with dementia and FNF without a higher risk of mortality.

Reliability of cup position in navigated THA in the lateral decubitus position using the 'flip technique'.

Malpositioning of the acetabular component in total hip arthroplasty (THA) increases the risk of dislocation, reduces the range of motion and may contribute to bearing surface wear. During computer assisted navigation, the anterior pelvic plane is registered intraoperatively by percutaneous palpation, but this may be unreliable. The aim of our study was to evaluate the reliability of imageless navigation in acetabular positioning employing data acquisition in the supine position and surgery in the lateral position ('flip technique'). We report 24 patients affected by primary osteoarthritis undergoing THA in which implants were placed with a conventional free-hand technique using the acetabular transverse ligament for cup orientation. For imageless navigation we used Orthopilot-Aesculap software. All patients had a postoperative computed tomography (CT) scan at three months, using previously validated dedicated software for cup orientation. Data collected using navigation software were compared with CT measurements. The mean acetabular inclination and anteversion recorded intra-operatively using navigation software were respectively 41°5' (SD: 9.61) and 9°5' (SD: 4.01) respectively. The mean inclination and anteversion calculated post-operatively by the CT based image software were 44°2' (SD 5.83) and 14°4' (SD 6.42) respectively. There was a statistically significant difference between the anteversion values (p=0.04). Therefore, the acquisition of parameters in the supine position with surgery performed in the lateral decubitus position creates unreliable data concerning cup anteversion using an imageless navigation system, and therefore the 'flip technique' cannot be recommended.

Navigated knee kinematics after tear of the ACL and its secondary restraints: preliminary results.

In this study we evaluated the role of the anterior cruciate ligament (ACL) and its secondary restraint in controlling knee stability using a navigation system. The purpose of this study was to evaluate the kinematics of the knee in different conditions of instability: ACL intact, after transection of the posterolateral (PL) bundle, after transection of the anteromedial (AM) bundle, and after lesion of the anterolateral femorotibial ligament (ALFTL). Anterior tibial translation and rotation were measured with a computer navigation system in 6 knees in whole fresh-frozen human cadavers by use of a manual maximum load. Anterior translation was evaluated at 30°, 60°, and 90° of flexion; rotation at 0°, 15°, 30°, 45°, 60°, and 90° of flexion. Cutting the PL bundle does not increase anterior translation and rotation of the knee. Cutting the AM bundle significantly increased the anteroposterior (AP) translation at 30° and 60° of flexion (P=.01), but does not increase rotation of the knee. Cutting the ALFTL increased anterior translation at 60° of flexion (P=.04) and rotation at 30°, 45°, and 60° of flexion (P=.03). The PL bundle does not affect anterior translation and rotation of the knee. The AM bundle is the primary restraint of the anterior translation but does not affect rotation of the knee. The lateral compartment becomes the primary restraint of rotation after ACL cut. The primary kinematic effect of an ACL injury is an increase in anterior tibial translation, but there is no significant change in maximum internal or external rotation. The lesion of the ALFTL increases tibial rotation and could be correlated to the pivot shift phenomenon.

Learning curve in tissue sparing total hip replacement: comparison between different approaches.

BACKGROUND: The tissue sparing surgery (TSS) concept means not only smaller incisions but also less tissue disruption, allowing decreased blood loss and improved function. However, TSS techniques can result in more complications related to the learning curve. The aim of this study was to compare the learning curve of an experienced surgeon with different TSS approaches for total hip replacement (THR) from a clinical and surgical point of view, focussing especially on complications related to the use of different geometric stems. MATERIALS AND METHODS: Sixty patients scheduled to be operated for a primary THR were enrolled in the study and were randomly assigned to surgery by one of three different TSS approaches: lateral with mini incision (group A), minimally invasive anterior (group B) and minimally invasive antero-lateral (group C). Results from the three TSS groups were compared with a control group of 149 patients (group D). RESULTS: Our results reveal significantly reduced blood loss in the TSS groups compared with the control group, with no differences between the TSS groups. We found better early functional scores in the two minimally invasive groups (anterior and anterolateral), and a lower rate of complications with the antero-lateral TSS approach. CONCLUSION: The antero-lateral TSS approach seems to be safer and less demanding than standard THR surgery, and is suitable for use with different stems.

Assessment of the initial stability of the Symax femoral stem with EBRA-FCA: a multicentric study of 85 cases.

We report a study of 85 Symax femoral stems that were followed at regular intervals with radiographs at 6, 12, 24 and 36 months. The radiological migration of each stem was measured using the computer-assisted EBRA -FCA method. In 30 cases in which the EBRA method did not provide a complete measurement another computer-assisted method (Roman version 1.7) was employed. In all cases the distal migration of the stems was minimal, The threshold migration value used to define the stability of a stem was 1.5 mm at 24 months. The mean migration within the first two years was -0.17 mm (+/- 0.3) at 6 months, -0.31 mm (+/- 0.4) at 12 months and -0.45 mm (+/- 0.5) at 24 months. Only two cases exceeded the threshold limit of 1.5 mm at the two-year follow-up, but both values were lower than 2 mm. In the 25 cases which reached three-year follow-up the mean distal migration was -0.84 (+/-0.7). In four of them the subsidence exceeded 1.5 mm, but only one exceeded 2 mm. These data represent a positive predictive factor for the minimal risk of future aseptic loosening.