Reaming Technique Research Articles

Reverse-reamed Intercalary Allograft: A Surgical Technique

Allograft reconstruction of large segmental intercalary bone defects after tumor resection is a well-accepted surgical technique. Although results generally have been satisfactory, nonunion at the allograft-host bone junction site remains a notable concern. Various reports have described attempts to enhance junctional healing with a variety of complex osteotomies, often complicating an already complex procedure. The use of an innovative reverse reaming technique can decrease the level of intraoperative difficulty mating the allograft-host junction and theoretically may improve junctional healing by enhancing stability and increasing the contact surface area.

Line-to-Line Reaming of Highly Porous Acetabular Components Improves Position and Reduces Variability of Component Placement

AbstractAccurate and precise acetabular component position in total hip arthroplasty remains challenging even for experienced, high-volume surgeons. Some variability may result from the press-fit technique of cementless components and maybe magnified by the use of highly porous cups with high-friction surfaces. The purpose of this study is to investigate the acetabular component positioning of a hemispherical, highly porous cup with line-to-line reaming compared with press-fit techniques. A retrospective cohort study was performed of 110 consecutive primary total hip arthroplasties performed by a single surgeon using a highly porous acetabular component. Half of the patients had the component implanted with a line-to-line reaming technique and the other half were implanted using a 1 mm press-fit technique. Postoperative radiographs were evaluated for component positioning and loosening at a minimum of 1 year postoperatively by two independent surgeons. Records were reviewed for subsequent surgery. There were no differences between the groups with respect to age, sex, body mass index, operative side, or acetabular component size. The press-fit group had an average abduction angle of 49.4 ± 5° and anteversion of 20.6 ± 7°. The line-to-line group had an average abduction angle of 45.02° [standard deviation (SD) 4.58] and anteversion of 25.42° (SD 4.44) and were statistically different from the press-fit group (p < 0.01). There was significantly less variability in the line-to-line group with respect to anteversion (F-test, p < 0.01) compared with the press-fit group. At most recent follow-up, there were no dislocations, revisions for any reason, or radiographic evidence of loosening in either group. Line-to-line reaming for highly porous cups can improve component positioning and reduce variability compared with press-fit techniques with no difference in fixation or other clinical outcome parameters.

Shell design and reaming technique affect deformation in mobile-bearing total hip arthroplasty acetabular components.

Press-fit acetabular components are susceptible to rim deformation. The inherent variability within acetabular reaming techniques may generate increased press-fit and, subsequently, additional component deformation. The purpose of this study was to analyze the insertion and deformation characteristics of acetabular components designed for dual-mobility systems based on component design, size, and reaming technique. Shell deformation was quantified in a validated worst-case scenario foam pinch model. Thin-walled, one-piece, and modular dual-mobility shells of varying size were implanted in under- and over-reamed cavities with insertion force measured and shell deformation assessed using digital image correlation. Increased shell size resulted in larger rim deformation in one-piece components, with a reduction in press-fit by 1 mm resulting in up to 48% reduction in insertion forces and between 23% and 51% reduction in shell deformation. Lower insertion forces and deformations were observed in modular components. Variability in acetabular reaming plays a significant role in the ease of implantation and component deformation in total hip arthroplasty. Modular components are less susceptible to deformation than thin-walled monoblock shells. Care should be taken to avoid excessive under-reaming, particularly in the scenario of large shell size and high-density patient bone stock.

Comparison of Head Center Position and Screw Fixation Options Between a Jumbo Cup and an Offset Center of Rotation Cup in Revision Total Hip Arthroplasty: A Computer Simulation Study

Jumbo acetabular cups are commonly used in revision total hip arthroplasty (THA). A straightforward reaming technique is used which is similar to primary THA. However, jumbo cups may also be associated with hip center elevation, limited screw fixation options, and anterior soft tissue impingement. A partially truncated hemispherical shell was designed with an offset center of rotation, thick superior rim, and beveled anterior and superior rims as an alternative to a conventional jumbo cup. A three dimensional computer simulation was used to assess head center position and safe screw trajectories. Results of this in vitro study indicate that a modified hemispherical implant geometry can reduce head center elevation while permitting favorable screw fixation trajectories into the pelvis in comparison to a conventional jumbo cup.

First Metatarsophalangeal Joint Arthrodesis Technique With Interposition Allograft Bone Block.

We present a technique of first metatarsophalangeal joint arthrodesis utilizing an interposition allograft bone block with a bipolar reaming technique that creates congruent fusion surfaces on both ends of the graft-host bone interface. In addition, we examined the union rates, fusion position, patient satisfaction, and functional outcome of this technique. Fifteen patients underwent first metatarsophalangeal joint arthrodesis with an interposition allograft bone block between September 2004 and October 2013. Charts and radiographs were reviewed. Six measures were compared on preoperative and postoperative radiographs. Clinical outcomes were measured using a telephone questionnaire, pre- and postoperative visual analog scale pain scale, and Foot and Ankle Ability Measure. Average follow-up was 46 weeks (range, 19 to 97). Thirteen of 15 (87%) patients achieved bony union at an average of 21 weeks. One patient underwent revision arthrodesis for their nonunion. Symptomatic hardware was removed in 3 cases. Improvement was noted in visual analog scale pain scores (6 to 2) and functional scores as measured by the Foot and Ankle Ability Measure. There were no postoperative wound complications or infections. Average length of the first ray on anteroposterior radiograph increased from 10.7 to 11.3 cm and from 10.0 to 10.7 cm on the lateral radiograph. Thirteen of 14 patients were very satisfied or satisfied. One patient expressed dissatisfaction with the procedure. One patient was not available for clinical follow-up. First metatarsophalangeal joint allograft bone block arthrodesis using the bipolar reaming technique achieved high bony union rates and satisfactory radiographic and clinical outcomes. This procedure was an effective salvage option for managing bone loss on 1 or both sides of the joint. Level IV, retrospective case series.

Achieving fixation in glenoids with superior wear using reverse shoulder arthroplasty

Superior glenoid wear is a common challenge with reverse shoulder arthroplasty and, if left uncorrected, can result in superior glenoid tilt, which increases the risk of aseptic glenoid loosening. This study evaluates the impact of an E2 superior defect on reverse shoulder glenoid fixation in composite scapulae after correction of glenoid tilt by use of 2 different glenoid reaming techniques: eccentric reaming and off-axis reaming. A superior glenoid defect was created in 14 composite scapulae. The superior defect was corrected by 2 different glenoid reaming techniques: (1) eccentric reaming with implantation of a standard glenoid baseplate and (2) off-axis reaming with implantation of a superior-augment glenoid baseplate. Each corrected superior-defect scapula was then cyclically loaded (along with a control group consisting of 7 non-worn scapulae) for 10,000 cycles at 750 N; glenoid baseplate displacement was measured for each group to quantify fixation before and after cyclic loading. Regardless of the glenoid reaming technique or the glenoid baseplate type, each standard and superior-augment glenoid baseplate remained well fixed in this superior-defect model scenario after cyclic loading. No differences in baseplate displacement were observed either before or after cyclic loading between groups. Our results suggest that either glenoid reaming technique may be used to achieve fixation in the clinically challenging situation of superior wear with reverse shoulder arthroplasty. Basic science, biomechanical study.

Comparison Study of Therapeutic Results of Closed Tibial Shaft Fracture with Intramedullary Nails Inserted with and without Reaming

Tibia fractures are the most common type of long bone fractures in US. This study aimed at comparing the therapeutic results of closed tibial shaft fracture with intramedullary nails inserted with and without reaming. In this randomized clinical trial study, 60 patients with a fracture of the tibia were examined. The patients were randomly divided into two groups. Thirty patients treated through inserting intramedullary nail with reaming technique (group A). The other 30 patients treated through inserting intramedullary nail without reaming technique (group B). After operation physical examination and control radiography were taken up to 6 month and results were compared. Sixty patients suffering from closed tibial diaphysis fractures were studied. Mean age of the group A and B were 40.24 +/- 12.32 and 38.42 +/- 14.28, respectively. Group A consisted of 24 (80%) males and 6 (20%) females while group B consisted of 24% females and 76% males. Considering fracture based on OTA criteria (p = 0.4) and severity of soft tissue damage based on Tscherne classification (p = 0.6), there was no statistically meaningful difference between groups A and B. The study demonstrated that degree of horizontal displacement, mean time of surgery, post-operation infection, organ shortness at the end of the follow-up period, organ deviation in patients of the group A was significantly more than that of the group B. Time required for callus formation (mean time of union), mean time of full weight bearing time and mean time of return to normal activities in group B was significantly more than that of the group A.

Comparison of Anterior Cruciate Ligament Tunnel Position and Graft Obliquity With Transtibial and Anteromedial Portal Femoral Tunnel Reaming Techniques Using High-Resolution Magnetic Resonance Imaging

Using 3-dimensional high-resolution magnetic resonance imaging (MRI), we sought to compare femoral and tibial tunnel position and resultant graft obliquity with single-bundle anterior cruciate ligament (ACL) reconstruction using transtibial (TT) or anteromedial (AM) portal femoral tunnel reaming techniques. Thirty patients were prospectively enrolled after primary, autogenous bone-patellar tendon-bone ACL reconstruction by 2 groups of high-volume, fellowship-trained sports medicine surgeons. With the TT technique, an external starting point was used to maximize graft obliquity and femoral footprint capture. By use of high-resolution MRI and imaging analysis software, bilateral 3-dimensional knee models were created, mirrored, and superimposed. Differences between centroids for each femoral and tibial insertion, as well as corresponding ACL/graft obliquity, were evaluated with paired t tests and 2-sided Mann-Whitney nonparametric tests, with P < .05 defined as significant. No significant differences were observed between groups in position of reconstructed femoral footprints. However, on the tibial side, AM centroids averaged 0.8 ± 1.9 mm anterior to native ACL centroids, whereas the TT group centered 5.23 ± 2.4 mm posterior to native ACL centroids (P < .001). Sagittal obliquity was closely restored with the AM technique (mean, 52.2° v. 53.5° for native ACL) but was significantly more vertical (mean, 66.9°) (P = .0001) for the TT group. In this clinical series, AM portal femoral tunnel reaming more accurately restored native ACL anatomy than the TT technique. Although both techniques can capture the native femoral footprint with similar accuracy, the TT technique requires significantly greater posterior placement of the tibial tunnel, resulting in decreased sagittal graft obliquity. When a tibial tunnel is drilled without the need to accommodate subsequent femoral tunnel reaming, more accurate tibial tunnel position and resultant sagittal graft obliquity are achieved. Level III, retrospective comparative study.

A Biomechanical Evaluation of Press-Fit Stem Constructs for Tumor Endoprosthetic Reconstruction of the Distal Femur

This study was designed to assess the biomechanical parameters of the older Kotz Modular Femur Tibia Reconstruction (Stryker Inc, Mahwah, NJ) stem and the newer Restoration and the unfluted Global Modular Replacement System (Stryker Inc, Mahwah, NJ) uncemented stems for use with tumor endoprostheses as well as to assess the optimal reaming technique for insertion of these stems. Fresh-frozen adult femora or composite distal femora were implanted with the uncemented stems. Separate experiments were performed to compare reaming technique and bone resection level. All constructs were mechanically tested for axial compression, lateral bending, and torsional stiffness and torque to failure. Results showed that the biomechanical performance of all the stems were similar with respect to each parameter. Cylindrical reaming was associated with a significantly higher torque to failure than flexible reaming in the diaphysis ( P = .006). Newer uncemented stems provide adequate initial biomechanical stability for implantation in the distal femur.

Tibial Tunnel Aperture Irregularity After Drilling With 5 Reamer Designs

Background: There is limited information in the literature on comparisons of antegrade versus retrograde reaming techniques and the effect on the creation of anterior cruciate ligament (ACL) tibial tunnel entry and exit apertures. Hypothesis: Proximal and distal apertures of ACL tibial tunnels, as created with different reamers, will be affected by type of reamer design. Study Design: Controlled laboratory study. Methods: Forty skeletally mature porcine tibias with bone mineral density values comparable with a young athletic population were included in this study. Five 9-mm reamer models were used (3 antegrade: A1, smooth-bore reamer; A2, acorn-head reamer; A3, flat-head reamer; 2 retrograde: R1, retrograde acorn reamer; R2, single-blade retrograde reamer), and a new reamer was used for each tibia (8 reamer-tibia pairs per reamer model). All specimens underwent micro–computed tomography scanning, and images were reconstructed and analyzed using 3-dimensional image analysis software. Aperture rim fractures were graded on a 0-IV scale that described the proportion of the fractured aperture circumference. Specimens with incomplete apertures were also recorded. Because of the unique characteristics of various tunnels, intratunnel characteristics were observed and recorded. Results: In sum, 1 proximal and 7 distal aperture rim fractures were found; 3, 0, and 4 distal aperture rim fractures were found with groups A1, A2, and A3, respectively. Incomplete apertures were more commonly found at the distal aperture (n = 15) than the proximal aperture (n = 8); there were no tibias with this finding at both apertures. All incomplete distal apertures occurred with the retrograde technique, and all incomplete proximal apertures occurred with the antegrade technique, most commonly with reamer design A3. An added finding of tunnel curvature at the distal aspect of the tunnel was observed in all 8 tibias with R1 reamers and 5 tibias with R2 reamers. This phenomenon was not observed in any of the tibias reamed with the antegrade technique. Conclusion: Anterior cruciate ligament tibial tunnel aperture characteristics were highly dependent on reamer design. Optimal proximal aperture characteristics were produced by the retrograde reamers, whereas optimal distal aperture characteristics were obtained with the antegrade reamers. In addition, a phenomenon of tunnel curvature in retrograde-type reamers was found, which may have effects on ACL graft or screw fixation. Clinical Relevance: Differences in tunnel aperture shapes and fractures depend on reamer design. This information is important for the creation of ACL reconstruction tunnels with different reamer designs.

Clamp-Assisted Reduction of High Subtrochanteric Fractures of the Femur

Subtrochanteric fractures can be a treatment challenge. The substantial forces that this region experiences and the fact that the proximal fragment is frequently displaced make accurate reduction and internal fixation difficult. The purpose of this study was to evaluate a series of patients who had undergone clamp-assisted reduction and intramedullary nail fixation to determine the impact of this technique on fracture union rates and reduction quality. Between December 2003 and January 2007, fifty-five consecutive patients with a displaced high subtrochanteric femoral fracture were treated with clamp-assisted reduction and intramedullary nail fixation at two level-I trauma centers. Two patients died, and nine were lost to follow-up. The remaining forty-four patients were followed until union or a minimum of six months. There were twenty-seven male and seventeen female patients with a mean age of fifty-five years. All were treated with an antegrade statically locked nail implanted with a reaming technique as well as the assistance of a reduction clamp placed through a small lateral incision. Nine patients were treated with a single supplemental cerclage cable. Radiographs were evaluated for the quality of the reduction and fracture union. Forty-three of the forty-four fractures united. All reductions were within 5° of the anatomic position in both the frontal and the sagittal plane. Thirty-eight (86%) of the forty-four reductions were anatomic. Six fractures had a minor varus deformity of the proximal fragment (between 2° and 5°). There were no complications. Surgical treatment of subtrochanteric femoral fractures with clamp-assisted reduction and intramedullary nail fixation techniques with judicious use of a cerclage cable can result in excellent reductions and a high union rate. Careful attention to detail is important to perform these maneuvers with minimal additional soft-tissue disruption.

Transtibial Versus Anteromedial Portal Drilling for Anterior Cruciate Ligament Reconstruction: A Cadaveric Study of Femoral Tunnel Length and Obliquity

To compare the obliquity and length of femoral tunnels prepared with transtibial versus anteromedial portal drilling for anterior cruciate ligament (ACL) reconstruction and identify potential risks associated with the anteromedial portal reaming technique. We used 18 human cadaveric knees (9 matched pairs) without ACL injury or pre-existing arthritis for the study. Femoral tunnels for ACL reconstruction were prepared by either a transtibial (n = 6) or anteromedial portal (n = 12) technique. For the anteromedial portal technique, a guidewire was advanced through the medial portal in varying degrees of knee flexion (100 degrees [n = 4], 110 degrees [n = 4], or 120 degrees [n = 4]) as measured with a goniometer. By use of a 6-mm femoral offset guide, two 6-mm femoral tunnels were reamed with the guide placed (1) as far posterior and lateral in the notch as possible and (2) as far medial and vertical in the notch as possible to define the range of maximal and minimal achievable coronal obliquity for each technique. All knees were imaged with high-resolution, 3-dimensional fluoroscopy to define (1) coronal tunnel obliquity relative to the lateral tibial plateau, (2) sagittal tunnel obliquity relative to the long axis of the femur, (3) intraosseous tunnel length, and (4) the presence of posterior cortical wall blowout. Data analysis was performed with a paired t-test and repeated-measures analysis of variance, with P < .05 defined as significant. Preparation of a vertical tunnel was possible with both transtibial and anteromedial portal drilling. The maximal achievable coronal obliquity, however, was significantly better with an anteromedial portal compared with transtibial drilling. However, 7 of 36 tunnels (19.4%) showed violation of the posterior tunnel wall, and all of these cases occurred with the anteromedial portal drilling technique. In addition, 1 of 6 oblique femoral tunnels (16.7%) drilled with the transtibial technique and 5 of 12 oblique femoral tunnels (41.7%) drilled with the anteromedial portal had an intraosseous length less than 25 mm. Increasing knee flexion with anteromedial portal drilling was associated with a significant reduction in tunnel length, increase in coronal obliquity, increase in sagittal obliquity, and increased risk of posterior wall blowout (P < .05). The anteromedial portal technique allows for slightly greater femoral tunnel obliquity compared with transtibial drilling. However, there is a substantially increased risk of critically short tunnels (<25 mm) and posterior tunnel wall blowout when a conventional offset guide is used. Increasing knee flexion with anteromedial portal drilling allows for greater coronal obliquity of the femoral tunnel but is accompanied by a greater risk of critically short tunnels and posterior wall compromise. Our findings provide insight into the potential risks and advantages of a transtibial versus an anteromedial femoral tunnel drilling technique in ACL reconstruction.

The Early Effects of Intramedullary Reaming of the Femur on Bone Mineral Density; an Experimental Study in Pigs

Both fracture and fracture treatment affect bone mineral density (BMD). BMD after standard intramedullary reaming of the femoral cavity and after reaming with a reamer-irrigator-aspirator (RIA) system were studied with the hypothesis that the RIA technique would lead to lower BMD levels. Dual-energy X-ray absorptiometry (DXA) was performed on the third day after operation with standard intramedullary nailing technique (n = 6) or RIA technique (n = 7) in intact femora of young Norwegian landrace pigs. Significantly lower BMD were found in the mid-shaft and total femur after reaming with the RIA technique compared to the non-operated femur. Traditional reaming technique resulted in significantly higher BMD in the distal -femur. The results of this study indicate that standard reaming increased BMD in the distal femur, suggesting compressive effects on trabecular bone. The RIA technique decreased BMD in the femoral diaphysis and total femur, suggesting removal of trabecular bone. A possible clinical impact of the findings remains to be investigated.

Clamp-Assisted Reduction of High Subtrochanteric Fractures of the Femur

Subtrochanteric fractures can be a treatment challenge. The substantial forces that this region experiences and the fact that the proximal fragment is frequently displaced make accurate reduction and internal fixation difficult. The purpose of this study was to evaluate a series of patients who had undergone clamp-assisted reduction and intramedullary nail fixation to determine the impact of this technique on fracture union rates and reduction quality. Between December 2003 and January 2007, fifty-five consecutive patients with a displaced high subtrochanteric femoral fracture were treated with clamp-assisted reduction and intramedullary nail fixation at two level-I trauma centers. Two patients died, and nine were lost to follow-up. The remaining forty-four patients were followed until union or a minimum of six months. There were twenty-seven male and seventeen female patients with a mean age of fifty-five years. All were treated with an antegrade statically locked nail implanted with a reaming technique as well as the assistance of a reduction clamp placed through a small lateral incision. Nine patients were treated with a single supplemental cerclage cable. Radiographs were evaluated for the quality of the reduction and fracture union. Forty-three of the forty-four fractures united. All reductions were within 5 degrees of the anatomic position in both the frontal and the sagittal plane. Thirty-eight (86%) of the forty-four reductions were anatomic. Six fractures had a minor varus deformity of the proximal fragment (between 2 degrees and 5 degrees ). There were no complications. Surgical treatment of subtrochanteric femoral fractures with clamp-assisted reduction and intramedullary nail fixation techniques with judicious use of a cerclage cable can result in excellent reductions and a high union rate. Careful attention to detail is important to perform these maneuvers with minimal additional soft-tissue disruption.

Thermal Necrosis Complicating Reamed Intramedullary Nailing of a Closed Tibial Diaphysis Fracture: A Case Report

A case report of thermal necrosis of the tibia after reamed intramedullary nailing is presented. Given the consequences of this complication, the proper use of reaming technique and equipment is emphasized.

Factors affecting acetabular bone loss during primary hip arthroplasty – A quantitative analysis using computer simulation

Background Although, various factors may affect the degree of acetabular bone loss during primary hip arthroplasty, they have not been quantified previously. Methods We assessed the influence of using various reamer diameters, designs and reaming depth on the amount of bone removed during acetabular preparation by simulated reaming in a three-dimensional pelvic model, using computer software. Findings The least amount of bone loss (6185 mm 3) providing optimal bone contact with the acetabular articular surface occurred with a 165° reamer design. Increase in reamer diameter, reaming depth and subtending angle of the reamer resulted in disproportionately large increase in the amount of bone resected compared to the relatively small increase in the reamer-bone contact area. Interpretation Surgeons must be aware of the relative influence of the reaming technique and the implant design on the amount of acetabular bone resection to optimize acetabular bone preservation during primary hip arthroplasty.

Intramedullary nailing in femoral shaft fractures. Evaluation of a group of 101 cases

The Authors analyse the results of intramedullary nailing in a group of 101 femoral shaft fractures. Used nails: Universal Synthes (62 cases), Russel-Taylor (14), Gamma long (10), uncannulated femoral nail (9), cannulated femoral nail (4) and proximal femoral nail (2). Stabilisation of the femoral shaft fracture was possible using a reamed technique in 91 cases, unreamed in 10. All nails were locked. Dynamisation was performed in 35 cases and was not in 66. The fracture heal was faster with the reaming and dynamisation technique. Ten fractures were open (5 Gustilo I, 5 Gustilo II) and stabilisation with Universal Synthes nail (8 cases), Russel-Taylor nail (1) and Gamma long nail (1) was performed. No infection was detected. Lung embolism (6) and deep vein thrombosis (3) occurred only in the case of reamed nails. All results confirm the locking nail system as the best treatment in the shaft fractures, especially with new-generation nails.

The biological and physiological effects of intramedullary reaming

This paper summarises the current knowledge on the effects of medullary reaming of long-bone fractures. Following a review of intramedullary vascular physiology, the consequences for vascularity, the autograft effects, the generation of heat, and fat embolism are outlined. Also, alternative reaming techniques are described.

Biological enhancement of tibial diaphyseal aseptic non-unions: the efficacy of autologous bone grafting, BMPs and reaming by-products

The mandatory stimulus that can optimise the healing pathway can be electrical, mechanical, biological, or a combination of all these parameters. A variety of means has been utilised for biological enhancement, including extracorporeal shock wave, electrical, ultrasound stimulation, the reaming technique of IM nailing, bone graft substitutes, osteogenic cells and bioactive molecules produced by tissue engineering techniques. The aim of this study is to present a review of the existing evidence for the efficacy of reaming, autologous bone grafting and the commercially available growth factors (BMP-2 and BMP-7) for the treatment of aseptic tibial non-unions. The gold standard method of enhancing bone healing in cases of tibial non-union remains the autologous bone graft. Autogenous bone grafts possess osteoconductive, osteoinductive properties and also osteoprogenitor cells. However, their harvesting is associated with high morbidity and many complications reaching percentages of 30%. Intramedullary reamed nailing, either used as an alternative fixation method or as an exchange to a wider implant, offers the unique biomechanical advantages of an intramedullary device, together with the osteoinductive stimulus of the by-products of reaming, and the aptitude for early weight-bearing and active rehabilitation. The safety of administration of the commercial distributed growth factors (BMP-2 and BMP-7), combined with the lack of the morbidity and the quantity restrictions that characterise autologous bone grafts, have given to this family of molecules a principal role between the other bone graft substitutes. On average the union rates reported in the 20 manuscripts that have been evaluated range from 58.3% to 100%, and the average time to union from 12.5 weeks to 48.4 weeks, indicating the significant discrepancies in the reported evidence and the multiplicity of different treatment strategies.

Alteration of the hip joint centre during acetabular reaming

Change of the hip joint centre location during preparation of the acetabular cavity for the acetabular component can affect the outcome of total hip arthroplasty. Deviations from the preoperative geometry can compromise an otherwise successful operation with regard to hip dislocations, leg length inequality and range of motion of the hip joint. Eighteen acetabula from pelvic specimens were measured before and after acetabular reaming to determine the change of hip centre location. Two different acetabular reamers were applied to the acetabular cavity: a chamfered reamer intended for minimal invasive hip surgery (MIS) and a conventional hemispherical reamer. An optical 3D scanning system created 3D models of the cavities prior to and after the reaming procedure. The two 3D models were merged into a single 3D model and displacements in all three dimensions were calculated The results showed no significant difference between MIS and conventional reaming with regard to transition vector length (p=0.9). The mean length of the transition vector was 3.6 mm (SD. 2.4 mm). Our findings suggest that the alteration of the hip centre location is not influenced by the changes made to the MIS reamers in comparison with conventional reamers. In comparison with previous studies the drift of the hip centre caused by the acetabular reaming is reduced due to new reaming techniques and prosthesis designs.