Invasive Anterolateral Approach Research Articles

Advances in study of surgical approaches and MRI evaluation of total hip arthroplasty

To review the research on different surgical approaches and MRI evaluation of total hip arthroplasty (THA), to clarify the possible muscle damage caused by different approaches, and to help clinicians avoid intraoperative muscle damage and identify the causes of certain muscle-related complications after operation. The research literature on different surgical approaches and MRI evaluation of THA at home and abroad was extensively reviewed to summarize the MRI performance of the posterior approach, modified direct lateral approach, direct anterior approach, and minimally invasive anterolateral approach (also called Orthopadische Chirurgie Munchen approach). The traditional posterior approach mainly damages the short external rotator muscle group and increases the incidence of postoperative dislocation; the piriformis-keeping posterior approach significantly improves the quality of the pyriformis tendon in the postoperative period, but it may lead to damage to the intrapelvic portion of the piriformis muscle. The modified direct lateral approach mainly damages the gluteus medius muscle, which increases the risk of postoperative claudication. The direct anterior approach mainly damages the vastus tensoris muscle and may result in damage to the short external rotator muscle group and the muscles around the incision. The minimally invasive anterolateral approach primarily damages the superior gluteal nerve, which subsequently leads to denervation of the broad fascial tensor fasciae latae, and this approach may also result in injury to the gluteus medius and gluteus minimus muscles. The muscle damage status significantly affects prognosis, and the minimally invasive approach is more suitable for elderly patients. MRI can clarify the different types of muscle damage caused by different surgical approaches. Minimally invasive approaches can reduce muscle damage and improve postoperative function compared with traditional approaches, and can benefit elderly patients more, but due to the small field, forcing to expand the surgical field will lead to unintended muscle damage and reduce postoperative function.

Learning curve of minimally invasive anterolateral approach in supine position for total hip arthroplasty

BackgroundTotal hip arthroplasty (THA) using minimally invasive anterolateral approach in the supine position (ALS) is reported to achieve good clinical outcomes including lower dislocation rates and early clinical recovery. However, minimally invasive ALS THA is technically challenging, especially among surgeons who are newly introduced to these techniques. This study aimed to evaluate the learning curves associated with minimally invasive ALS THA. MethodsThis study divided 720 primary THAs with a minimally invasive ALS approach into three groups based on the number of previous procedures per surgeon (A:1–100, B:101–200, C: >201). Surgical time and perioperative complications were compared among the three groups. ResultsPerioperative complications were seen in 8.0% of patients, including periprosthetic fractures (4.2%), surgical site infection (1.3%), stem subsidence (1.0%), nerve palsy (0.6%), dislocation (0.4%), major bleeding (0.4%), and liner malseating (0.1%). The rate of perioperative complications in each group was 8.6% (30 patients), 10.9% (22 patients), and 3.5% (6 patients) in groups A, B, and C, respectively. Group C has a significantly lower rate than other groups. Group B has significantly higher surgical site infection rate than other groups. No statistically significant difference was found in the surgical times among the three groups. ConclusionThe learning curve associated with minimally invasive ALS THA was approximately 200 cases in terms of perioperative complications. Moderately experienced surgeons should always pay careful attention to avoid complications during ALS THA until they perform >200 cases.

Assessment of the Damage to Hip Abductor Muscles in Primary Total Hip Arthroplasty With a Minimally Invasive Anterolateral Approach With or Without Trochanteric Flip Osteotomy

BackgroundAlthough introduction of minimally invasive techniques via anterolateral approaches considerably decreased prolonged limp after total hip arthroplasty (THA), potential damage to the abductor muscles is still a concern. This study aimed to evaluate the residual damage after primary THA with two types of anterolateral approach by assessing fatty infiltration and atrophy of the gluteus medius (GMed) and gluteus minimus (GMin) muscles. MethodsWe retrospectively analyzed 100 primary THAs using computed tomography; surgeries were performed by detaching the anterior part of the abductor muscles with a bone fragment (anterolateral approach with trochanteric flip osteotomy) or without it (anterolateral approach without trochanteric flip osteotomy). The change in radiodensities (RDs), cross-sectional areas (CSAs), and clinical scores preoperatively and at 1 year after operation were evaluated. ResultsThe RD and CSA of GMed increased 1 year postoperatively in 86 and 81% of patients, respectively, while RD and CSA of GMin decreased in 71 and 94%, respectively. The improvement of RD of GMed was more frequently seen in the posterior rather than the anterior part, while the GMin decreased in both parts. The RD decrease of GMin was significantly lower in the anterolateral approach with trochanteric flip osteotomy group than the anterolateral approach without trochanteric flip osteotomy group (P = .0250). However, there was no difference in the clinical scores between the two groups. The change in the RD of GMed was the only factor that correlated with clinical scores. ConclusionThe two anterolateral approaches both improved the RD of GMed, recovery of which was significantly associated with postoperative clinical scores. Although the two approaches showed different recovery patterns in GMin until 1 year after THA, both showed similar improvements in clinical scores.

Robotic arm-assisted total hip arthroplasty via a minimally invasive anterolateral approach in the supine position improves the precision of cup placement in patients with developmental dysplasia of the hip

BackgroundThis study evaluated the accuracy of the cup alignment angles and spatial cup positioning on computed tomography (CT) images in patients with osteoarthritis secondary to developmental dysplasia of the hip (DDH) who underwent total hip arthroplasty (THA) using a minimally invasive technique via an anterolateral approach in the supine position according to whether a robotic arm-assisted system or a CT-based navigation system was used. MethodsWe reviewed 60 robotic arm-assisted (RA)-THA cases and 174 navigation-assisted (NA)-THA cases. After propensity score matching, there were 52 hips in each group. Postoperative cup alignment angles and position were assessed by superimposition of a three-dimensional cup template onto the actual implanted cup using postoperative CT images with pelvic coordinates matching the preoperative planning. ResultsThe mean absolute error of the inclination angle and the anteversion angle between the preoperative planning and the postoperative measurement was significantly smaller in the RA-THA group (inclination, 1.1° ± 0.9; anteversion, 1.3° ± 1.0) than in the NA-THA group (inclination, 2.2° ± 1.5; anteversion, 3.3° ± 2.5). For acetabular cup positioning, the mean discrepancy between the preoperative planning and the postoperative measurement was 1.3 ± 1.3 mm on the transverse axis, 2.0 ± 2.0 mm on the longitudinal axis, and 1.3 ± 1.7 mm on the sagittal axis in the RA-THA group and 1.6 ± 1.4 mm, 2.6 ± 2.3 mm, and 1.8 ± 1.3 mm, respectively, in the NA-THA group. High precision of cup positioning was observed in both groups with no statistically significant difference. ConclusionRobotic arm-assisted THA using a minimally invasive technique via an anterolateral approach in the supine position allows accurate cup placement in patients with DDH.

Gait analysis after total hip arthroplasty by direct minimally invasive anterolateral approach: A controlled study

IntroductionClinical and functional improvement after minimally invasive total hip arthroplasty (THA) has become increasingly controversial. The minimally invasive anterolateral approach (MIALA) allows rapid recovery resulting in a reduced need for rehabilitation. Alterations in muscle and static balance have previously been demonstrated. Results in the context of quantified gait analysis (QGA) and MIALA compared to an asymptomatic population remain unknown beyond one year postoperatively. Thus, the main objective of this controlled study was to compare the spatiotemporal parameters of gait, obtained using a QGA, beyond one year postoperatively in subjects operated on for THA by MIALA, with a group of asymptomatic subjects of the same age. The secondary objectives of the study were to compare the other QGA and EMG data acquired in operated subjects with asymptomatic subjects. HypothesisWe hypothesized that QGA and EMG parameters would not normalize beyond one year postoperatively. Patients and methodsThirty-one subjects were recruited, including 16 patients (68 years old; IQR: 65–70) who underwent MIALA, at 15.5 months postoperatively (IQR: 13–17) and 15 asymptomatic subjects (62 years old; IQR: 61–71). Subjects underwent QGA and maximal isometric muscle force tests on the gluteus medius, gluteus maximus, Tensor Fascia Lata (TFL) and Sartorius muscles. Spatiotemporal gait parameters were the primary endpoint. The other QGA parameters: kinetics (characteristic values of vertical ground reaction forces, peak hip moments) and kinematics (hip joint amplitudes and pelvic mobility in the frontal and sagittal plane) constituted the secondary criteria. ResultsFive subjects were excluded for unrestored offset. Walking speed was lower in operated patients (1.03m/s versus 1.18m/s, p=0.005). Maximal isometric muscle force moments were lower in patients operated on for the gluteus maximus and medius as well as the TFL (p<0.005). The vertical ground reaction forces were lower for the operated patients for the loading phase (FzFCmax, p=0.001), the single stance phase (FzSPmin, p=5.05.10−2) and the swing phase (FzTOmax, p=0.0002). The moments were lower in the sagittal plane for the operated patients (0.6N.m for the operated versus 1.1N.m for the asymptomatic, p=0.02). The pelvic amplitudes in the sagittal plane were lower for operated patients (3.3° versus 7.2°, p=0.05). DiscussionOur hypothesis appears to be validated. Gait deficits persisted beyond one year postoperatively after THA with MIALA. A decrease in walking speed, maximal isometric muscle force of the gluteus medius and gluteus maximus and TFL was observed, as well as a decrease in propulsive force and peak hip moment. Functionally, these results could signify muscle damage following surgery, requiring rehabilitation for improved muscle function. Level of proofIII: Non-randomized controlled trial.

Periprosthetic Femoral Fractures in Cementless Short Versus Straight Stem Total Hip Arthroplasty: A Propensity Score Matched Analysis

BackgroundRecent studies indicate a decreased risk of periprosthetic femoral fractures (PFFs) in cementless total hip arthroplasty (THA) for short compared to straight stems. However, the results are still inconclusive. Therefore, we retrospectively investigated the rate of PFFs within the first year between cementless short and straight stem THA. MethodsA 1:1 propensity score matching of 3,053 THAs was performed. Two groups including 1,147 short stem THAs implanted through a minimally invasive antero-lateral approach and 1,147 straight stem THAs implanted through a transgluteal Hardinge approach were matched. The rates of PFFs and fracture patterns were compared between both stem types. Risk factors for PFFs were analyzed by multivariate regression analyses. ResultsThe overall rate of PFFs was 1.7% in short stem THA and 3.2% in straight stem THA (P = .015). Postoperatively detected Vancouver A fractures occurred significantly more often in straight stem THA (P = .002), while the occurrence Vancouver B fractures did not differ significantly (P = .563). The risk of PFFs was significantly increased for women in straight stem THA (Odds ratio (OR) 2.620; Confidence Interval (CI) 1.172-5.856; P = .019). Increasing age showed a significantly increased odds ratio in short stem (OR 1.103; CI 1.041-1.169, P < .001) and straight stem THA (OR 1.057; CI 1.014-1.101, P = .008). ConclusionShort stem THA reduces Vancouver Type A PFFs in the trochanteric region compared to straight stem THA, while Vancouver Type B fractures are comparable. Increasing age is a significant risk factor for both stem types, while the risk for PFFs in women was only significantly increased in the straight stem group.

Comparison Between Minimally Invasive Anterolateral and Conventional Posterior Hip Approaches for Hemiarthroplasty in Hip Fractures

Purpose: To compare the results between minimally invasive anterolateral and conventional posterior hip approaches for hemiarthroplasty in hip fractures. Methods: The elderly patients who had undergone hip hemiarthroplasty for hip fractures in Maharaj Nakhon Si Thammarat Hospital, were randomly divided into two groups: minimally invasive anterolateral and posterior approach groups Data were collected from March 2020 to November 2021, which included the duration of the surgery, length of the surgical wound, intraoperative bleeding volume, postoperative days of walking with a walker, morphine dosage for pain relief, and postoperative complications. Results: No significant difference (P-value &gt; 0.05) was found between the baseline data of patients in both the groups, which included sex, age, body mass index, underlying musculoskeletal disease, and drug usage. The minimally invasive anterolateral approach group used an average surgical time of 53.48 ± 8.22 min, while the conventional posterior approach group required 65 ± 20.41 min; the length of the surgical wound was 7.78 ± 0.87 and 13.78 ± 1.37 cm, respectively; the volume of intraoperative bleeding was 82.17 ± 48.94 and 195.65 + 163.24 ml, respectively; the postoperative days of walking with a walker were 3.09 ± 0.92 and 6.59 ± 2.52 days, respectively; and the postoperative analgesic doses of morphine were 6.59 ± 2.80 and 11.09 ± 3.89 mg, respectively. The blood transfusion was required in 4 patients in the minimally invasive anterolateral approach group, while it was required in 14 patients in the conventional posterior approach group. Statistically significant (P-value &lt; 0.05). Postoperative complications included, prosthetic hip joint dislocation in a patient in each group and sciatic nerve neurapraxia in a patient in the conventional posterior approach group. Conclusions: Hip hemiarthroplasty with the minimally invasive anterolateral approach in elderly patients with hip fractures was found to be superior to the conventional posterior approach.

Minimally Invasive Anterolateral Approach Total Hip Arthroplasty Using Bone Preserving Short Femoral Stem: Intermediate Term Clinical and Radiological Results

Aim: The objective of this study was to evaluate the intermediate term clinical and radiological results of a Bone preserving short stem hip implant being operated through a minimally invasive anterolateral hip approach. Methods: In 20 consecutive patients suffering from osteoarthritis with 25 affected hip joints (five cases were bilateral), the clinical and radiological results of 25 hip arthroplasties performed in one hospital between October 2009 and May 2014 through a minimally invasive anterolateral approach using a cementless short stem prosthesis type Aida and a cementless cup type Ecofit with a ceramic-on-ceramic pairing were evaluated prospectively. The median age of patients at time of surgery was 60 years (range, 42-71 years), 15 male (4 were bilateral) and 5 female patients (one was bilateral) were included in the study. The median clinical follow up was 30 months (range, 2-88 months) and the median radiological follow up was 30 months (range, 2-88 months). Results: Harris Hip Score improved from a median preoperative value of 53 to a median postoperative value of 96 (range, 73-100) at follow up. 22 hips (88%) showed an excellent postoperative Harris Hip Score, 2 hips (8%) a good postoperative Harris Hip Score and one hip (4%) a fair postoperative Harris Hip Score. Only two patients complained of postoperative thigh pain. Regarding patient satisfaction, 15 patients (60%) were very satisfied, 10 patients (40%) were satisfied. None was unsatisfied. Radiological analysis showed that 19 stems (76%) were with stable bony ingrowth, two cases (8%) showed stable fibrous ingrowth. Four cases need further follow up for proper evaluation of stem fixation. Conclusion: The intermediate term survival of the Aida short stem hip implant being operated through a minimally invasive anterolateral hip approach is very promising and achieving the goals of a standard hip arthroplasty.

MRI assessment of minimally invasive anterolateral approaches in total hip arthroplasty

IntroductionTotal hip arthroplasty (THA) on a minimally invasive anterolateral (MIAL) approach frequently leads to gluteus minimus and gluteus medius lesions, and sometimes to tensor fasciae latae (TFL) denervation. We therefore developed compensatory strategies, which we assessed on pre- and post-operative MRI: 1) to assess gluteus minimus and gluteus medius fatty infiltration (FI), 2) to assess TFL FI, and 3) to assess FI in the other periarticular muscles. HypothesisThe modified MIAL approach reduces the rate of gluteus minimus and gluteus medius lesion. Materials and methodsA continuous prospective single-surgeon series of THA using a MIAL approach included 25 patients. Femoral implantation was performed with the hip in extension so as to distance the proximal femur from the gluteals, avoiding muscle trauma. The superior gluteal nerve branch in the space between the gluteus medius and TFL, running toward the TFL, was systematically released and protected. MRI was performed preoperatively and at 3 months and 1 year post-surgery. FI was analyzed according to the Goutallier classification in all periarticular muscles. ResultsOne patient lacked preoperative MRI and was excluded, leaving 24 patients, for 72 MRIs. In 10/24 patients (41.7%) the gluteus minimus and in 8/24 patients (33.3%) the anterior third of the gluteus medius showed ≥2 grade increase in FI between preoperative and 1-year MRI, with significant increases in both at 3 months (p<0.001) and 1 year (p<0.001). At least a 2 grade increase in FI at 1 year was seen in 1 patient (4.2%) in the TFL, in 2 (8.3%) in the piriformis, and in 1 (4.2%) in the obturator internus. There were no significant differences in FI between preoperative, 3-month or 1-year MRI in any other periarticular muscles. ConclusionFemoral implantation in hip extension did not reduce the rate of gluteal lesions, which remained frequent. In contrast, release of the superior gluteal nerve branch could be effective in conserving TFL innervation. Some rare lesions of the proximal part of the pelvi-trochanteric muscles were also observed. Level of evidenceIV, Prospective case series.

Minimally invasive anterolateral approach versus direct anterior approach total hip arthroplasty in the supine position: a prospective study based on early postoperative outcomes

BackgroundMinimally anterolateral approach (MAA) and direct anterior approach (DAA) have been reported as beneficial for total hip arthroplasty (THA) due to their ability to reduce postoperative pain and lead to quicker rehabilitation by preserving muscle insertions. As there is an ongoing debate on the effect of these two approaches on early postoperative outcomes, this prospective study aimed to assess the difference in early clinical, radiological, and patient-reported outcomes between the two minimally invasive approaches.MethodsA total of 98 patients, 50 in the MAA group and 48 in the DAA group, were included in the study. Patients with complete data were evaluated preoperatively and postoperatively at 2, 6, and 12 weeks. Clinical measurements, including the ability to climb stairs and walk, 6-min walk test (6MWT), the Forgotten Joint Scale (FJS-12), Japanese Orthopedic Association (JOA) Hip scores, radiological evaluation, and complications were analyzed.ResultsThere were no significant differences in clinical outcomes and implant alignments between MAA and DAA groups. In regards to patient-reported outcomes, the FJS-12 was significantly higher in the MAA group compared to group DAA at 2 and 6 weeks postoperatively. However, there was no significant difference in the FJS-12 between the two groups 12 weeks after surgery. The differences also included shorter operative times (62.4 ± 9.05 min vs. 71 ± 8.01 min), less blood loss (132.6 ± 43.31 ml vs. 159.23 ± 37.25 ml), lower Hb drop (29.56 ± 8.02 g/L vs. 36.4 ± 7.12 g/L), and fewer blood transfusions in the MAA group (4.0% vs. 18.8%). The incidence of the lateral femoral cutaneous nerve (LFCN) neuropraxia after surgery was 7 (14.6%) in the DAA group and 0 in the MAA group. One fracture was found in each group and managed conservatively.ConclusionMAA and DAA approach yielded excellent and similar early clinical outcomes. However, better patient-reported outcomes could be achieved by MAA THA. The MAA resulted in a safer approach associated with shorter operative times, less blood loss, lower Hb drop, fewer blood transfusions, and LFCN neuropraxia than DAA. A longer follow-up is needed to further examine differences between these procedures.

Digital templating cementless short stem total hip arthroplasty: is there a difference in planning adherence between the direct anterior approach and minimally invasive anterolateral approach?

PurposeMinimally invasive approaches (MIS) in total hip arthroplasty (THA) show inconsistent findings regarding planning adherence in digital templating. The purpose of this study is to evaluate any difference in planning adherence between the direct anterior approach (DAA) and an anterolateral MIS approach (AL MIS) in cementless short stem THA.MethodsA single surgeon series of 222 THAs in 208 patients with an uncemented short curved stem and a bi-hemispherical acetabular cup were screened for inclusion. A total of 118 THAs were implanted via the DAA and 72 THAs via the AL MIS were included. The planning adherence for the offset option, stem size and the acetabular cup were retrospectively evaluated.ResultsPlanning adherence for cup size (perfect match: p = 0.763; ± 1 size: p = 0.124), offset option (0.125) and stem size (perfect match: p = 0.275; ± 1 size: p = 0.552) did not show any statistical significance. Preoperative diagnosis of avascular necrosis of the femoral head in AL MIS approach (OR 6.045; CI 1.153–31.696) or mild hip dysplasia in the general cohort poses (OR 11.789; CI 1.386–100.293) a significant risk for inadequate prediction of the offset option. Conclusion: digital templating for THA with an uncemented short curved stem and a bi-hemispherical acetabular cup show comparable results between a direct anterior approach and a minimally invasive anterolateral approach in supine position. Surgeons should be aware of a low planning adherence for this type of short stem in minimally invasive approaches.ConclusionDigital templating for THA with an uncemented short curved stem and a bi-hemispherical acetabular cup show comparable results between a direct anterior approach and a minimally invasive anterolateral approach in supine position. Surgeons should be aware of a low planning adherence for this type of short stem in minimally invasive approaches.

Minimally invasive anterolateral approach versus lateral transmuscular approach for total hip arthroplasty: A systematic review and meta-analysis

BackgroundTotal hip arthroplasty (THA) using a minimally invasive (MI) approach is a commonly performed procedure, and several approaches are now being used clinically. The MI anterolateral (MIAL) approach is one of the MI approaches used in clinical practice. Whether the MIAL approach is superior to non-MI approaches remains controversial. To resolve this controversy, we performed a systematic review and a meta-analysis of results of THA procedures that used the MIAL approach. We assessed whether the MIAL approach was superior to the lateral transmuscular (LT) approach in terms of operative time, operative blood loss, radiological parameters, and clinical outcomes. MethodsWe performed a methodical search for all literature published on PubMed, Web of Science, and the Cochrane Library, and pooled data using the RevMan software. A p value < 0.05 was considered statistically significant. We calculated the mean differences (MD) for continuous data with 95% confidence intervals (CI) for each outcome. ResultsThis meta-analysis included 6 studies. Pooled results indicated no statistically significant differences between the groups in terms of operative time (MD = 5.13, 95% CI -2.49 to 12.75, p = 0.19), cup abduction angle (MD = 1.64, 95% CI -1.32 to 4.60, p = 0.28), and cup anteversion angle (MD = 0.75, 95% CI -1.09 to 2.59, p = 0.43). Operative blood loss was significantly greater in those who underwent THA via the MIAL approach than those who underwent THA via the LT approach (MD = 68.01, 95% CI 14.69 to 121.33, p = 0.01). The postoperative Harris hip score (HHS) assessed at the time of final follow-up was significantly higher in those who underwent THA via the MIAL approach than those who underwent THA via the LT approach (MD = 1.41, 95% CI 0.50 to 2.33, p = 0.002). ConclusionWe conclude that the MIAL approach is superior to the LT approach in terms of clinical outcomes. Level of evidenceLevel Ⅱ

Obesity in short stem total hip arthroplasty using a minimally invasive supine anterolateral approach\u2014a risk factor for short-term complications?

PurposeObesity is associated with increased risk for surgical complications in total hip arthroplasty (THA). The impact of obesity on short-term complication in minimally invasive (MIS) anterolateral approach is not well known. Therefore, this study was conducted to evaluate the early complications within the first 90 days after THA using a MIS anterolateral approach with a short-curved stem stratified by Body Mass Index (BMI).Patients and methodsA single centre consecutive series of 1052 hips in 982 patients (index surgery 2014–2019) with a short-curved stem and press fit cup implanted using a MIS anterolateral approach in supine position were screened for inclusion. Inclusion criteria were defined as end-stage primary osteoarthritis of the hip. Eventually, 878 implantations in 808 patients were included and stratified by body mass index (BMI). Peri-operative complications, within the first 90 days after surgery, were retrospectively evaluated.ResultsSeverely obese patients (BMI ≥ 35 kg/m2) and morbidly obese patients (BMI ≥ 40 kg/m2) demonstrated a significantly increased operation time (p < 0.001) and a higher risk for general surgical complications (p = 0.015) (odds ratio (OR) = 4.365; OR = 4.985), periprosthetic joint infection (PJI) (p = 0.001) (OR = 21.687; OR = 57.653), and revision (OR = 8.793; OR = 20.708).ConclusionThe risk for early PJI and overall surgical complications in MIS anterolateral approach is significantly increased in severely and morbidly obese patients. This leads to a significantly higher risk for revision surgery after index surgery within the first 90 days. A BMI above 35 kg/m2 is the clear threshold for increased risk of PJI in MIS anterolateral THA with a short curved stem. As the surgical complications are comparable to other approaches, MIS anterolateral short stem THA is also feasible with increasing BMI.

Digital templating for the implantation of a curved short hip stem with an anterolateral MIS approach shows gender differences in digital templating

PurposeDigital templating shows reliable accuracy for straight stem systems. In recent years, the implantation of short stems through minimally invasive approaches has gained more popularity. Minimally invasive approaches (MIS) show the risk of undersizing femoral components. Therefore, we questioned the planning adherence for a curved short stem and a bi-hemispherical acetabular cup implanted through an anterolateral MIS approach.MethodsA consecutive series of 964 hips (index surgery between 2014 and 2019) with Fitmore® curved short stem and Allofit/-S® acetabular cup (both ZimmerBiomet Inc, Warsaw, IN) were included. Preoperative digital templating was conducted anterior–posterior (AP) digital radiographs of the hip using mediCAD® version 5.1 (Hectec GmbH, Altdorf, Germany). The templates of acetabular and femoral components (offset option and stem size) were retrospectively evaluated for general adherence, and according to sex, BMI and planner’s experience.ResultsPlanning adherence for the exact offset option was 70.6 and 21.6% for exact offset option and stem size. Adherence for acetabular cup ± 1 size was 74.8%. A significant difference between male and female patients for the offset option could be found (p = 0.03, z = −2983). In 22.5% of male patients, an offset option one size higher and in 12.3% of female patients an offset option one size smaller than templated was used intraoperativelyConclusionDigital templating for the Fitmore® stem in cementless THA with a minimally invasive anterolateral approach shows comparable planning adherence to the existing literature for this cementless short stem. However, a lower planning adherence was detected compared to conventional straight stem systems. In male patients, the femoral offset is frequently undersized and in female patients frequently oversized compared to the preoperative plan. Surgeons should be aware of this difficulty in digital templating for Fitmore® hip stem.

Low rate of early periprosthetic fractures in cementless short-stem total hip arthroplasty using a minimally invasive anterolateral approach

PurposeMinimally invasive (MIS) approaches in combination with short stems have gained popularity in recent years in total hip arthroplasty (THA). A decreased risk for periprosthetic femoral fractures (PFFs) is reported for cementless short-stem THA, but in contrast to other approaches, the risk factors for PFFs for short-stem THA using MIS anterolateral approach in supine position are not described in literature.MethodsA single-center consecutive series of 1052 hips in 982 patients, performed between 2014 and 2019 with a short curved stem and a press fit using an MIS anterolateral approach in supine position, was retrospectively screened for inclusion. Fourteen patients were lost to follow-up. Therefore, 1038 THAs in 968 patients were included. Risk factors for intra- and postoperative PFFs within 90 days were analyzed. We investigated for sex, age, body mass index (BMI), diagnosis, and laterality.ResultsIn total, 18 PFFs (1.7%) occurred. Intraoperative fracture occurred in ten cases ( 0.9%), with another eight cases (0.8%) occurring postoperatively. Increased American Society of Anesthesiologists (ASA) Score was a significant risk factor for PFF (p = 0.026), whereas sex (p = 0.155), age (p = 0.161), BMI (p = 0.996), and laterality (p = 1.000) were not. Seven PFFs (0.7%) required revision arthroplasty.ConclusionCementless short-stem THA using the MIS anterolateral approach is a procedure with a low number of PFFs within 90 days from index surgery. Fracture rates are comparable to other MIS approaches, and comparable femoral short stems are used. Age, sex, and BMI were not identified as risk factors of PFF, while risk for PFF increased with ASA Score.Level of EvidenceLevel IV

Improving MiniHip femoral prosthesis positioning using a cross‐laser projection system in total hip arthroplasty by an anterolateral supine approach

BackgroundThe authors developed a cross‐laser projection system (CLP) to place a femoral neck‐sparing short stem using the minimally invasive anterolateral supine approach in total hip arthroplasty. This study aimed to verify the utility of CLP.MethodsThirty joints were assessed with the MiniHip (Corin). The authors compared femoral component implantation with a patient‐specific femoral osteotomy guide (PSG) for the femoral neck‐cut (PSG group), with the CLP attached to the rasp handle to irradiate the cross‐laser to the target of PSG (CLP group), and without PSG or CLP (control group).ResultsIn the CLP group, the positional deviation of anteversion, anterior/posterior tilt and varus/valgus placement of the stem postoperatively were 1.8° ± 0.2°, 2.0° ± 2.0° and 2.0° ± 0.1°, respectively. The positional deviation of anteversion (p < 0.001) and anterior/posterior tilt (p = 0.036) were significantly smaller than those in the other groups.ConclusionsCLP improves the accuracy of MiniHip femoral prosthesis placement.

A novel surgical approach and technique and short-term clinical efficacy for the treatment of proximal humerus fractures with the combined use of medial anatomical locking plate fixation and minimally invasive lateral locking plate fixation

Background and hypothesisThe typical anterolateral approach is widely used to treat proximal humerus fractures with lateral locking fixation. However, lateral fixation cannot completely avoid medial reduction loss and varus deformity especially in the cases of an unstable medial column. We present a novel medial surgical approach and technique together with a minimally invasive lateral locking plate to fix proximal humerus fractures with an unstable medial column.Materials and methodsWe performed an anatomical study and reported 8 cases of proximal humerus fractures with unstable medial columns treated with plate fixation through a minimally invasive anterolateral approach and medial approach. All surgeries were performed by the same single surgeon. Patients were followed clinically and radiographically at 1, 3, 6, and 12 months postoperatively.ResultsThere was a safe region located at the medial part of the proximal humerus just beneath the articular surface. An anatomical medial locking proximal humerus plate could be placed in the medial column and did not affect the axillary nerve, blood supply of the humeral head, or stability of the shoulder joint. Successful fracture healing was achieved in all 8 cases. The function and range of motion of the shoulder joint were satisfactory 24 months postoperatively, with an average Constant score (CS) of 82.8. No reduction loss (≥ 10° in any direction), screw cutout, nonunion, or deep infection occurred.ConclusionsThe combined application of medial anatomical locking plate fixation and minimally invasive lateral locking plate fixation is effective in maintaining operative reduction and preventing varus collapse and implant failure in proximal humerus fractures with an unstable medial column.

Low pelvic incidence is a risk factor for intraoperative complications in minimally invasive anterolateral approach for total hip arthroplasty.

Minimally invasive anterolateral approach (ALA) has gained popularity in recent years as better postoperative functional recovery and lower risk of postoperative dislocation are claimed. However, difficulties for femur exposure and intraoperative complications during femoral canal preparation and component placement have been reported. This study analyses the effect of anatomical factors on difficulties for femoral access and intraoperative complications with a modified minimally invasive ALA. 310 consecutive patients who had primary unilateral total hip arthroplasty (THA) by single surgeon using same approach and technique, and being suitable for EOS were included. All patients underwent pre- and postoperative standing and sitting full-body EOS acquisitions and pelvic and femoral parameters were measured. All intra- and postoperative complications for femoral preparation and implantation were assessed. Intraoperative complications included femoral fractures and difficulties for femoral exposure. 10 patients (3.2%) had intraoperative femoral fractures (2 greater trochanter, 8 calcar). Difficult access to the proximal femur was reported for 10 other patients (3.2%). Patients with intraoperative complications presented a significantly lower pelvic incidence (PI) than patients without intraoperative complications (mean PI: 39.4° vs. 56.9°, p < 0.001). The pelvic incidence can be useful to detect anatomically less favourable patients for THA implantation using ALA.

Achievement of optimal implant alignment using taper wedge stems with cup-first THA through the MIS antero-lateral approach.

Combined anteversion (CA) technique (stem-first procedure) has become generally accepted as an ideal means to achieve optimal CA value in THA. However, we hypothesized that CA technique for patients with various native femoral anteversions could pose a risk of anterior or posterior cup protrusion. In the present study, we examined whether it is possible to use the taper wedge stem to change the stem version to achieve optimal CA while avoiding cup protrusions with the cup-first procedure through minimally invasive (MIS) antero-lateral approach. Eighty-one patients underwent cup-first THA with a taper wedge stem. The acetabular cup was placed following the preoperative planning of the cup alignment to avoid anterior cup protrusions using CT-based navigation. Following the CA theory, anteversion of the taper wedge stem was changed to the target anteversion from the patient's native femoral anteversion. The native femoral anteversion, the change in version angle of the stem, postoperative CA and the length of anterior cup protrusions were evaluated in postoperative CT measurements. The native femoral anteversion averaged 25.7° ± 8.9° (range 8°-45°). Cases with increased and decreased stem anteversion were observed in 42 hips (51.8%) and 33 hips (40.7%), respectively. The amount of increased and decreased version angles averaged 7.7° ± 4.8° (range 2°-21°) and 7.8° ± 5.1° (range 2°-20°), respectively. Postoperative CA values averaged 36.7° ± 3.4° (range 29.4°-44.2°) and anterior cup protrusion length averaged 2.0mm ± 2.6mm (0 ~ 8.8mm) in axial view and 0.4mm ± 1.0mm (0 ~ 3.6mm) in sagittal view. Anterior cup protrusion of more than 10mm was not observed in any hips. This procedure can be considered as an option to achieve optimal CA anteversion while avoiding anterior cup protrusion in THA.

The Minimally Invasive Anterolateral Approach (MIS-AL)- 11-Year Results of Cementless Total Hip Arthroplasty

Minimally invasive approaches in total hip arthroplasty continue to be a debated topic with a number of controversial views...