MiniHip is designed to give patients the advantages of a traditional hip replacement whilst also preserving the natural anatomy. MiniHip potentially allows for future revisions and so provides a pre-primary intervention for patients who may require treatment options into the second, third and fourth decades. Conserving bone MiniHip is designed to minimise bone loss during the time of operation, and promote physiological loading that may maintain good bone stock into the long term. Preserving soft tissue Suitable for all approaches, and ideally for the direct anterior, MiniHip is designed to be less invasive to soft tissues, potentially helping with patient recovery. Restoring biomechanics With an implant profile that preserves the femoral neck and follows the natural curvature of the medial calcar, MiniHip is designed to restore biomechanics for multiple anatomies. 5A* ODEP rating MiniHip has been awarded 5A* rating by the Orthopaedic Data Evaluation Panel (ODEP) 7 which is the highest rating achievable at 5 years.
Preserving the natural anatomy and restoring patient biomechanics
3 Conserving bone Considerably more bone resorption occurs in Gruen zone 7 with a standard long-stem low-resection cementless prosthesis 1,2. Neck-retaining short stems have the potential to be more bone preserving than conventional hip prostheses and may help to minimise periprosthetic bone loss when correctly sized and implanted. Physiological loading The MiniHip stem transmits 2.5 times more load into the proximal femur compared to a standard neck resection prosthesis 3. Having a higher neck resection assists the stem in transmitting more physiological load proximally which may reduce bone resorption seen in standard cementless total hip replacements. 1. Trochanter conserving MiniHip is designed to follow the natural anatomy: there is no lateral flare and the entry point avoids the greater trochanter. 2. Diaphyseal sparing The length and design of MiniHip allows for more bone preservation of the medullary canal than traditional THR. In addition, the distal tip of MiniHip is polished to reduce the risk of an increase in bone mineral density from occurring at this point. 3. Neck preserving MiniHip neck resection is intended to preserve the neck and calcar to assist in promoting more natural physiological loading, unlike conventional THR [2]. 1 2 3
Preserving soft tissue Restoring biomechanics MiniHip is an ideal implant for use with all approaches but is particularly suited to the direct anterior approach (a smaller incision and soft tissue sparing procedure) as it follows the natural anatomy by going round the corner of the calcar. Direct anterior approach patients have earlier discharge and mobilisation as compared to patients who receive the posterior approach 4, potentially helping to facilitate patient recovery and a faster return to activity. MiniHip offers a unique way of restoring biomechanics for different patient anatomies. With a CT scan-based design, MiniHip is not constrained in its placement by a conventional, intrusive lateral profile, or by gaining fixation in the metaphysis/diaphysis. This, combined with retention of the femoral neck, enables MiniHip to restore the biomechanics of multiple anatomies including highly anteverted femurs 5. Early and mid term clinical results with MiniHip illustrate reproducibility of: CCD to less than 0.6 6 Femoral offset to less than 3mm 6 Leg length to less than 1mm 6 15 10 5 0-5 -10-15 -20 CCD angle 2 1.5 1 0.5 0-0.5-1 -1.5 Offset 1 0.8 0.6 0.4 0.2 0-0.2-0.4 0.6 Leg length
References: 1. Yeoman M, Lowry C, Cizinauskas A, Vincent G, Simpson D, Collins D. Bone remodelling following THR; short stems are less likely to lead to bone resorption. International Society for Technology in Arthroplasty, September 2011, Leuven, Belgium. 2. Huiskes R. Biomechanics of uncemented total hip arthroplasty for long stem stress shield. Current Opinion in Orthopaedics 1996;7:32. 3. Simpson DJ, Lowry C, Yeoman M, Cizinauskas A, Vincent G, Collins SN. Short stem total hip replacement: are you being conservative enough? British Hip Society, Torquay, March 2011. 4. Martin CT, Pugely AJ, Gao Y, Clark CR. A comparison of hospital length of stay and short term morbidity between the anterior and posterior approaches to total hip arthroplasty. Journal of Arthroplasty 2013 May;28(5):849-854. 5. Kreuzer S. 43rd annual advances in Arthroplasty care. Harvard 2013 6. Jerosch J, Grasselli C, Kothny C. Early and mid term clinical results with MiniHip short stem replacement. OUP 2012:1(5):202-207. 7. ODEP (Orthopaedic Data Evaluation Panel) is an independent body set up by National Health Purchasing and Supply Agency (PASA, subsequently replaced by NHS Supply Chain) as a response to National Institute for Health and Care Excellence (NICE) issuing guidance relating to Total hip replacement and resurfacing arthroplasty. ODEP assesses whether a device has reached a specified clinical benchmark for implant survivorship and translates these into ratings consisting of a number and a letter. The number represents the number of years for which the product s performance has been evidenced. The letter represents the strength of evidence (data) presented by the manufacturer (A = strong evidence, B = acceptable evidence). Implant survivorship greater than 97% survivorship at 3 years (ODEP rating 3A or 3B); greater than 95% survivorship at 5 years (ODEP rating 5A or 5B); greater than 93% survivorship at 7 years (ODEP rating 7A or 7B); greater than 90% survivorship at 10 years (ODEP rating 10A or 10B). A star* has been added to the rating system following revised guidelines from NICE in February 2014, in which a benchmark replacement rate of less than 1 in 20 (5%) at 10 years was defined. The star* is awarded where products are evidenced to comply with this benchmark. A* represents very strong evidence above A and B. Latest ODEP ratings can be found at www.odep.org.uk 2017 Corin P No I1182 Rev3 02/2017 CR65